From 570746dc69ea32f2a017aedb51b8a763df631844 Mon Sep 17 00:00:00 2001
From: Kevin Reed <kevin.a.reed@gmail.com>
Date: Mon, 31 Jul 2023 09:57:08 -0500
Subject: [PATCH 01/21] 1.1, 1.2

---
 Work/bounce.py |  7 +++++++
 Work/hello.py  |  1 +
 Work/sears.py  | 27 +++++++++++++++++++++++++++
 3 files changed, 35 insertions(+)
 create mode 100644 Work/hello.py
 create mode 100644 Work/sears.py

diff --git a/Work/bounce.py b/Work/bounce.py
index 3660ddd82..652b1444c 100644
--- a/Work/bounce.py
+++ b/Work/bounce.py
@@ -1,3 +1,10 @@
 # bounce.py
 #
 # Exercise 1.5
+
+current_height = 100 # meters
+fall_fraction = 3 / 5 # fraction of from_height
+
+for i in range(1, 11):
+    current_height *= fall_fraction
+    print(i, round(current_height, 4))
\ No newline at end of file
diff --git a/Work/hello.py b/Work/hello.py
new file mode 100644
index 000000000..6b561325f
--- /dev/null
+++ b/Work/hello.py
@@ -0,0 +1 @@
+print('Suh, Dude?')
\ No newline at end of file
diff --git a/Work/sears.py b/Work/sears.py
new file mode 100644
index 000000000..f36953f1e
--- /dev/null
+++ b/Work/sears.py
@@ -0,0 +1,27 @@
+# One morning, you go out and place a dollar bill
+# on the sidewalk by the Sears tower in Chicago.
+# Each day thereafter, you go out double the number
+# of bills. How long does it take for the stack of
+# bills to exceed the height of the tower?
+
+bill_thickness = 0.11 * 0.001 # meters (0.11 mm)
+sears_height = 442 # height (meters)
+num_bills = 1
+day = 1
+
+def print_day(day, num_bills, height):
+    remaining_height = sears_height - height
+    print('{:<10}{:<21}{:<20}{:<30}'
+        .format(
+            f'day: {day}',
+            f'num_bills: {num_bills}',
+            f'height: {height}',
+            f'height_remaining: {round(remaining_height, 2)}'))
+    
+
+while num_bills * bill_thickness < sears_height:
+    print_day(day, num_bills, num_bills * bill_thickness)
+    day += 1
+    num_bills *= 2
+
+print_day(day, num_bills, num_bills * bill_thickness)
\ No newline at end of file

From f4497408a3963fb39e2244149a425107e0f24383 Mon Sep 17 00:00:00 2001
From: Kevin Reed <kevin.a.reed@gmail.com>
Date: Mon, 31 Jul 2023 11:38:15 -0500
Subject: [PATCH 02/21] add tests and test runner helper

---
 Work/bounce.py        | 13 ++++++++-----
 Work/bounce_test.py   | 17 +++++++++++++++++
 Work/requirements.txt |  2 ++
 Work/work.ps1         | 18 ++++++++++++++++++
 4 files changed, 45 insertions(+), 5 deletions(-)
 create mode 100644 Work/bounce_test.py
 create mode 100644 Work/requirements.txt
 create mode 100644 Work/work.ps1

diff --git a/Work/bounce.py b/Work/bounce.py
index 652b1444c..739f61c9d 100644
--- a/Work/bounce.py
+++ b/Work/bounce.py
@@ -2,9 +2,12 @@
 #
 # Exercise 1.5
 
-current_height = 100 # meters
-fall_fraction = 3 / 5 # fraction of from_height
+def bounce():
+    current_height = 100 # meters
+    fall_fraction = 3 / 5 # fraction of from_height
 
-for i in range(1, 11):
-    current_height *= fall_fraction
-    print(i, round(current_height, 4))
\ No newline at end of file
+    for i in range(1, 11):
+        current_height *= fall_fraction
+        print(i, round(current_height, 4))
+
+bounce()
\ No newline at end of file
diff --git a/Work/bounce_test.py b/Work/bounce_test.py
new file mode 100644
index 000000000..2612b10cf
--- /dev/null
+++ b/Work/bounce_test.py
@@ -0,0 +1,17 @@
+from bounce import *
+
+def test_main(capfd):
+    bounce()
+    
+    out, err = capfd.readouterr()
+    assert out == """1 60.0
+2 36.0
+3 21.6
+4 12.96
+5 7.776
+6 4.6656
+7 2.7994
+8 1.6796
+9 1.0078
+10 0.6047
+"""
diff --git a/Work/requirements.txt b/Work/requirements.txt
new file mode 100644
index 000000000..653c63ce5
--- /dev/null
+++ b/Work/requirements.txt
@@ -0,0 +1,2 @@
+pytest==7.4.0
+pytest-watch==4.2.0
diff --git a/Work/work.ps1 b/Work/work.ps1
new file mode 100644
index 000000000..5631580ca
--- /dev/null
+++ b/Work/work.ps1
@@ -0,0 +1,18 @@
+param([string]$Command)
+
+switch ($Command) {
+    "env" {
+        python -m venv env
+        iex $PSScriptRoot\env\Scripts\Activate.ps1
+        pip install -r $PSScriptRoot\requirements.txt
+    }
+    "test" {
+        pytest $PSScriptRoot -q
+    }
+    "test:watch" {
+        ptw $PSScriptRoot -- -q
+    }
+    default {
+        Write-Error "Command '$Command' not found."
+    }
+}
\ No newline at end of file

From cc99c990ab8647b2fba57aecc4a5fe2938f275a1 Mon Sep 17 00:00:00 2001
From: Kevin Reed <kevin.a.reed@gmail.com>
Date: Mon, 31 Jul 2023 21:56:44 -0500
Subject: [PATCH 03/21] 1.3

---
 Work/mortgage.py      | 33 +++++++++++++++++++++++++++++++++
 Work/mortgage_test.py |  7 +++++++
 Work/sears.py         |  1 -
 Work/work.ps1         | 10 +++++-----
 4 files changed, 45 insertions(+), 6 deletions(-)
 create mode 100644 Work/mortgage_test.py

diff --git a/Work/mortgage.py b/Work/mortgage.py
index d527314e3..a0163174e 100644
--- a/Work/mortgage.py
+++ b/Work/mortgage.py
@@ -1,3 +1,36 @@
 # mortgage.py
 #
 # Exercise 1.7
+
+def mortgage(extra_payment_start_month=0,
+             extra_payment_end_month=0,
+             extra_payment=0.0):
+    principal = 500000.0
+    rate = 0.05
+    default_payment = 2684.11
+    paid = 0.0
+    month = 0
+
+    while principal > 0:
+        month += 1
+        payment = default_payment
+
+        if month >= extra_payment_start_month and month <= extra_payment_end_month:
+            payment += extra_payment
+        
+        if payment > principal:
+            payment = principal
+            principal = 0
+        else:
+            principal = principal * (1 + rate / 12) - payment
+        
+        paid = paid + payment
+        print(month, paid, principal)
+    
+    print('Total paid', round(paid, 2))
+    print('Months', month)
+    return round(paid, 2)
+
+print('1.7', mortgage())
+print('1.8', mortgage(1, 12, 1000))
+print('1.9', mortgage(61, 108, 1000))
\ No newline at end of file
diff --git a/Work/mortgage_test.py b/Work/mortgage_test.py
new file mode 100644
index 000000000..75dbcefef
--- /dev/null
+++ b/Work/mortgage_test.py
@@ -0,0 +1,7 @@
+from mortgage import mortgage
+
+def test_mortgage_1_7():
+    assert round(mortgage(), 1) == 966266.9
+
+def test_mortgage_1_8():
+    assert round(mortgage(1, 12, 1000), 2) == 927989.46
\ No newline at end of file
diff --git a/Work/sears.py b/Work/sears.py
index f36953f1e..7f946c2ae 100644
--- a/Work/sears.py
+++ b/Work/sears.py
@@ -17,7 +17,6 @@ def print_day(day, num_bills, height):
             f'num_bills: {num_bills}',
             f'height: {height}',
             f'height_remaining: {round(remaining_height, 2)}'))
-    
 
 while num_bills * bill_thickness < sears_height:
     print_day(day, num_bills, num_bills * bill_thickness)
diff --git a/Work/work.ps1 b/Work/work.ps1
index 5631580ca..e77726a12 100644
--- a/Work/work.ps1
+++ b/Work/work.ps1
@@ -2,15 +2,15 @@ param([string]$Command)
 
 switch ($Command) {
     "env" {
-        python -m venv env
-        iex $PSScriptRoot\env\Scripts\Activate.ps1
-        pip install -r $PSScriptRoot\requirements.txt
+        & python -m venv env
+        & $PSScriptRoot\env\Scripts\Activate.ps1
+        & pip install -r $PSScriptRoot\requirements.txt
     }
     "test" {
-        pytest $PSScriptRoot -q
+        & pytest $PSScriptRoot -q
     }
     "test:watch" {
-        ptw $PSScriptRoot -- -q
+        & ptw $PSScriptRoot -- -q
     }
     default {
         Write-Error "Command '$Command' not found."

From df8619076b09102a08d6ab66ea05d389e5af78e7 Mon Sep 17 00:00:00 2001
From: Kevin Reed <kevin.a.reed@gmail.com>
Date: Mon, 31 Jul 2023 22:21:43 -0500
Subject: [PATCH 04/21] 1.17

---
 Work/mortgage.py | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/Work/mortgage.py b/Work/mortgage.py
index a0163174e..2009f0e6e 100644
--- a/Work/mortgage.py
+++ b/Work/mortgage.py
@@ -11,6 +11,7 @@ def mortgage(extra_payment_start_month=0,
     paid = 0.0
     month = 0
 
+    print(f'{"Mo":>3} {f"Paid":>11} {f"Principal":>11}')
     while principal > 0:
         month += 1
         payment = default_payment
@@ -25,12 +26,12 @@ def mortgage(extra_payment_start_month=0,
             principal = principal * (1 + rate / 12) - payment
         
         paid = paid + payment
-        print(month, paid, principal)
+        print(f'{month:>3} {f"${paid:,.2f}":>11} {f"${principal:,.2f}":>11}')
     
-    print('Total paid', round(paid, 2))
-    print('Months', month)
+    print('------------------')
+    print(f'Total paid: ${round(paid, 2):,.2f}')
+    print('Months:    ', month)
+    print('------------------')
     return round(paid, 2)
 
-print('1.7', mortgage())
-print('1.8', mortgage(1, 12, 1000))
-print('1.9', mortgage(61, 108, 1000))
\ No newline at end of file
+mortgage(61, 108, 1000)
\ No newline at end of file

From ddfc62fc5efab1ca4212c97ff672f597ddd96313 Mon Sep 17 00:00:00 2001
From: Kevin Reed <kevin.a.reed@gmail.com>
Date: Tue, 1 Aug 2023 22:32:06 -0500
Subject: [PATCH 05/21] 1.27

---
 Work/pcost.py      | 13 +++++++++++++
 Work/pcost_test.py |  4 ++++
 2 files changed, 17 insertions(+)
 create mode 100644 Work/pcost_test.py

diff --git a/Work/pcost.py b/Work/pcost.py
index e68aa20b4..631d305c7 100644
--- a/Work/pcost.py
+++ b/Work/pcost.py
@@ -1,3 +1,16 @@
 # pcost.py
 #
 # Exercise 1.27
+
+def pcost():
+    with open('Data/portfolio.csv', 'rt') as f:
+        next(f) # skip header
+        cost = 0.0
+        for line in f:
+            row = line.split(',')
+            shares = int(row[1])
+            stock_cost = float(row[2])
+            cost += shares * stock_cost
+    return cost
+
+print(f'Total cost ${pcost():,.2f}')
\ No newline at end of file
diff --git a/Work/pcost_test.py b/Work/pcost_test.py
new file mode 100644
index 000000000..5ee490a38
--- /dev/null
+++ b/Work/pcost_test.py
@@ -0,0 +1,4 @@
+from pcost import pcost
+
+def test_pcost():
+    assert pcost() == 44671.15
\ No newline at end of file

From af5042fc1ad2bbbb5478b98b5fcc405b3e698e68 Mon Sep 17 00:00:00 2001
From: Kevin Reed <kevin.a.reed@gmail.com>
Date: Tue, 1 Aug 2023 22:38:17 -0500
Subject: [PATCH 06/21] 1.31

---
 Work/pcost.py      | 18 +++++++++++-------
 Work/pcost_test.py |  7 +++++--
 2 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/Work/pcost.py b/Work/pcost.py
index 631d305c7..463c8e050 100644
--- a/Work/pcost.py
+++ b/Work/pcost.py
@@ -2,15 +2,19 @@
 #
 # Exercise 1.27
 
-def pcost():
-    with open('Data/portfolio.csv', 'rt') as f:
+def pcost(filename):
+    '''Returns the total cost of the portfolio'''
+    with open(filename, 'rt') as f:
         next(f) # skip header
         cost = 0.0
         for line in f:
-            row = line.split(',')
-            shares = int(row[1])
-            stock_cost = float(row[2])
-            cost += shares * stock_cost
+            try:
+                fields = line.split(',')
+                shares = int(fields[1])
+                stock_cost = float(fields[2])
+                cost += shares * stock_cost
+            except ValueError:
+                print(f'Could not parse {line}')
     return cost
 
-print(f'Total cost ${pcost():,.2f}')
\ No newline at end of file
+print(f'Total cost ${pcost("Data/portfolio.csv"):,.2f}')
\ No newline at end of file
diff --git a/Work/pcost_test.py b/Work/pcost_test.py
index 5ee490a38..d679f38af 100644
--- a/Work/pcost_test.py
+++ b/Work/pcost_test.py
@@ -1,4 +1,7 @@
 from pcost import pcost
 
-def test_pcost():
-    assert pcost() == 44671.15
\ No newline at end of file
+def test_pcost_1_27():
+    assert pcost('Data/portfolio.csv') == 44671.15
+
+def test_pcost_1_31():
+    assert pcost('Data/missing.csv') == 27381.15
\ No newline at end of file

From e922a4df0ee0b6d7da2a25a723fe73be88328e28 Mon Sep 17 00:00:00 2001
From: Kevin Reed <kevin.a.reed@gmail.com>
Date: Tue, 1 Aug 2023 22:41:32 -0500
Subject: [PATCH 07/21] 1.32

---
 Work/pcost.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/Work/pcost.py b/Work/pcost.py
index 463c8e050..7e27aae92 100644
--- a/Work/pcost.py
+++ b/Work/pcost.py
@@ -1,20 +1,21 @@
 # pcost.py
 #
 # Exercise 1.27
+import csv
 
 def pcost(filename):
     '''Returns the total cost of the portfolio'''
     with open(filename, 'rt') as f:
-        next(f) # skip header
+        rows = csv.reader(f)
+        next(rows) # skip header
         cost = 0.0
-        for line in f:
+        for fields in rows:
             try:
-                fields = line.split(',')
                 shares = int(fields[1])
                 stock_cost = float(fields[2])
                 cost += shares * stock_cost
             except ValueError:
-                print(f'Could not parse {line}')
+                print(f'Could not parse {fields}')
     return cost
 
 print(f'Total cost ${pcost("Data/portfolio.csv"):,.2f}')
\ No newline at end of file

From a204fa29b2360c02882ace3751e84aa2a6bb6f5d Mon Sep 17 00:00:00 2001
From: Kevin Reed <kevin.a.reed@gmail.com>
Date: Tue, 1 Aug 2023 22:45:38 -0500
Subject: [PATCH 08/21] 1.33

---
 Work/pcost.py         |  4 +---
 Work/pcost_command.py | 12 ++++++++++++
 2 files changed, 13 insertions(+), 3 deletions(-)
 create mode 100644 Work/pcost_command.py

diff --git a/Work/pcost.py b/Work/pcost.py
index 7e27aae92..ba4d0032f 100644
--- a/Work/pcost.py
+++ b/Work/pcost.py
@@ -16,6 +16,4 @@ def pcost(filename):
                 cost += shares * stock_cost
             except ValueError:
                 print(f'Could not parse {fields}')
-    return cost
-
-print(f'Total cost ${pcost("Data/portfolio.csv"):,.2f}')
\ No newline at end of file
+    return cost
\ No newline at end of file
diff --git a/Work/pcost_command.py b/Work/pcost_command.py
new file mode 100644
index 000000000..d06f207e6
--- /dev/null
+++ b/Work/pcost_command.py
@@ -0,0 +1,12 @@
+# Excersize 1.33
+
+from pcost import pcost
+import sys
+
+if len(sys.argv) == 2:
+    filename = sys.argv[1]
+else:
+    filename = 'Data/portfolio.csv'
+
+cost = pcost(filename)
+print(f'Total cost ${cost:,.2f}')
\ No newline at end of file

From eea0cfb19e194ea5fccaf332f458cd646e6b0a42 Mon Sep 17 00:00:00 2001
From: Kevin Reed <kevin.a.reed@gmail.com>
Date: Tue, 1 Aug 2023 22:46:13 -0500
Subject: [PATCH 09/21] 1.33

---
 Work/pcost_command.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Work/pcost_command.py b/Work/pcost_command.py
index d06f207e6..38012374e 100644
--- a/Work/pcost_command.py
+++ b/Work/pcost_command.py
@@ -3,6 +3,8 @@
 from pcost import pcost
 import sys
 
+print(sys)
+
 if len(sys.argv) == 2:
     filename = sys.argv[1]
 else:

From 7fefd9b295b1081bb9ce77f6d0edac61473d324e Mon Sep 17 00:00:00 2001
From: Kevin Reed <kevin.a.reed@gmail.com>
Date: Tue, 1 Aug 2023 22:47:54 -0500
Subject: [PATCH 10/21] 1.33

---
 Work/pcost_command.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Work/pcost_command.py b/Work/pcost_command.py
index 38012374e..4f7d1d531 100644
--- a/Work/pcost_command.py
+++ b/Work/pcost_command.py
@@ -3,9 +3,10 @@
 from pcost import pcost
 import sys
 
-print(sys)
+print(sys.argv)
+print()
 
-if len(sys.argv) == 2:
+if len(sys.argv) > 1:
     filename = sys.argv[1]
 else:
     filename = 'Data/portfolio.csv'

From ee283eb843840848269d6070b0c74ce81e877b75 Mon Sep 17 00:00:00 2001
From: Kevin Reed <kevin.a.reed@gmail.com>
Date: Sun, 6 Aug 2023 17:49:21 -0500
Subject: [PATCH 11/21] 2.7

---
 Work/Data/stocksim.py | 16 ++++++++--
 Work/bounce_test.py   |  2 +-
 Work/mortgage.py      |  2 +-
 Work/report.py        | 73 +++++++++++++++++++++++++++++++++++++++++++
 Work/report_test.py   | 33 +++++++++++++++++++
 Work/requirements.txt |  1 +
 Work/work.ps1         | 12 +++++--
 7 files changed, 131 insertions(+), 8 deletions(-)
 create mode 100644 Work/report_test.py

diff --git a/Work/Data/stocksim.py b/Work/Data/stocksim.py
index 52ebe4185..5ef258b56 100755
--- a/Work/Data/stocksim.py
+++ b/Work/Data/stocksim.py
@@ -112,13 +112,23 @@ def update(self):
     def incr(self,dt):
         self.time += dt
         if self.index < (len(self.history) - 2):
-            while self.index < (len(self.history) - 2) and self.time >= self.history[self.index+1][3]:
+            while self.index < (len(self.history) - 2) and \
+                self.time >= self.history[self.index+1][3]:
                 self.index += 1
         self.update()
 
     def make_record(self):
-        return [self.name,round(self.price,2),self.date,minutes_to_str(self.time),round(self.change,2),self.open,round(self.high,2),
-                round(self.low,2),self.volume]
+        return [
+            self.name,
+            round(self.price, 2),
+            self.date,
+            minutes_to_str(self.time),
+            round(self.change, 2),
+            self.open,
+            round(self.high, 2),
+            round(self.low, 2),
+            self.volume
+        ]
 
 class MarketSimulator(object):
     def __init__(self):
diff --git a/Work/bounce_test.py b/Work/bounce_test.py
index 2612b10cf..5d3569863 100644
--- a/Work/bounce_test.py
+++ b/Work/bounce_test.py
@@ -1,4 +1,4 @@
-from bounce import *
+from bounce import bounce
 
 def test_main(capfd):
     bounce()
diff --git a/Work/mortgage.py b/Work/mortgage.py
index 2009f0e6e..b79395b68 100644
--- a/Work/mortgage.py
+++ b/Work/mortgage.py
@@ -11,7 +11,7 @@ def mortgage(extra_payment_start_month=0,
     paid = 0.0
     month = 0
 
-    print(f'{"Mo":>3} {f"Paid":>11} {f"Principal":>11}')
+    print(f'{"Mo":>3} {"Paid":>11} {"Principal":>11}')
     while principal > 0:
         month += 1
         payment = default_payment
diff --git a/Work/report.py b/Work/report.py
index 47d5da7b1..0e89a5355 100644
--- a/Work/report.py
+++ b/Work/report.py
@@ -1,3 +1,76 @@
 # report.py
 #
 # Exercise 2.4
+import csv
+from pprint import pprint
+
+def read_portfolio(filename):
+    portfolio = []
+    with open(filename, 'rt') as f:
+        rows = csv.reader(f)
+        next(rows) # skip header
+        for fields in rows:
+            try:
+                holding = (fields[0], int(fields[1]), float(fields[2]))
+                portfolio.append(holding)
+            except ValueError:
+                print(f'Could not parse {fields}')
+    return portfolio
+
+def read_portfolio_2_5(filename):
+    portfolio = []
+    with open(filename, 'rt') as f:
+        rows = csv.reader(f)
+        next(rows) # skip header
+        for fields in rows:
+            try:
+                holding = {
+                    'name': fields[0],
+                    'shares': int(fields[1]),
+                    'price': float(fields[2])
+                }
+                portfolio.append(holding)
+            except ValueError:
+                print(f'Could not parse {fields}')
+    return portfolio
+
+def read_prices_2_6(filename):
+    prices = {}
+    with open(filename, 'rt') as f:
+        rows = csv.reader(f)
+        # next(rows) # skip header
+        for row in rows:
+            if (len(row) == 0):
+                continue
+
+            try:
+                prices[row[0]] = float(row[1])
+            except ValueError:
+                print(f'Could not parse {row}')
+
+    pprint(prices)
+    return prices
+
+def get_gainloss_2_7(stocksFilename, pricesFilename):
+    prices = read_prices_2_6(pricesFilename)
+    stocks = read_portfolio_2_5(stocksFilename)
+
+    total_value = 0.0
+    total_market_value = 0.0
+    total_gain_loss = 0.0
+    for stock in stocks:
+        stock['current_value'] = stock['price'] * stock['shares']
+        stock['market_value'] = prices[stock['name']] * stock['shares']
+        stock['gain_loss'] = stock['market_value'] - stock['current_value']
+
+        total_value += stock['current_value']
+        total_market_value += stock['market_value']
+        total_gain_loss += stock['gain_loss']
+
+        print('{name:s} {gain_loss:,.2f}'.format_map(stock))
+
+    print(f'Total value: {total_value:,.2f}')
+    print(f'Total market value: {total_market_value:,.2f}')
+    print(f'Total gain/loss: {total_gain_loss:,.2f}')
+
+    return total_gain_loss
\ No newline at end of file
diff --git a/Work/report_test.py b/Work/report_test.py
new file mode 100644
index 000000000..7508675bd
--- /dev/null
+++ b/Work/report_test.py
@@ -0,0 +1,33 @@
+from report import read_portfolio, read_portfolio_2_5, read_prices_2_6, get_gainloss_2_7
+
+def test_read_portfolio_2_4():
+    portfolio = read_portfolio('Data/portfolio.csv')
+    assert portfolio == [
+        ('AA', 100, 32.2),
+        ('IBM', 50, 91.1),
+        ('CAT', 150, 83.44),
+        ('MSFT', 200, 51.23),
+        ('GE', 95, 40.37),
+        ('MSFT', 50, 65.1),
+        ('IBM', 100, 70.44)
+    ]
+
+def test_read_portfolio_2_5():
+    portfolio = read_portfolio_2_5('Data/portfolio.csv')
+    assert portfolio == [
+        {'name': 'AA', 'shares': 100, 'price': 32.2}, {'name': 'IBM', 'shares': 50, 'price': 91.1},
+        {'name': 'CAT', 'shares': 150, 'price': 83.44}, {'name': 'MSFT', 'shares': 200, 'price': 51.23},
+        {'name': 'GE', 'shares': 95, 'price': 40.37}, {'name': 'MSFT', 'shares': 50, 'price': 65.1},
+        {'name': 'IBM', 'shares': 100, 'price': 70.44}
+    ]
+
+def test_read_prices_2_6():
+    prices = read_prices_2_6('Data/prices.csv')
+    assert prices['AA'] == 9.22
+    assert prices['AXP'] == 24.85
+    assert prices['IBM'] == 106.28
+    assert prices['MSFT'] == 20.89
+
+def test_get_gainloss_2_7():
+    gain_loss = get_gainloss_2_7('Data/portfolio.csv', 'Data/prices.csv')
+    assert round(gain_loss, 2) == -15985.05
\ No newline at end of file
diff --git a/Work/requirements.txt b/Work/requirements.txt
index 653c63ce5..5dbd22163 100644
--- a/Work/requirements.txt
+++ b/Work/requirements.txt
@@ -1,2 +1,3 @@
 pytest==7.4.0
 pytest-watch==4.2.0
+ruff==0.0.282
diff --git a/Work/work.ps1 b/Work/work.ps1
index e77726a12..a74ccfb21 100644
--- a/Work/work.ps1
+++ b/Work/work.ps1
@@ -1,9 +1,9 @@
 param([string]$Command)
 
 switch ($Command) {
-    "env" {
-        & python -m venv env
-        & $PSScriptRoot\env\Scripts\Activate.ps1
+    "venv" {
+        & python -m venv venv
+        & $PSScriptRoot\venv\Scripts\Activate.ps1
         & pip install -r $PSScriptRoot\requirements.txt
     }
     "test" {
@@ -12,6 +12,12 @@ switch ($Command) {
     "test:watch" {
         & ptw $PSScriptRoot -- -q
     }
+    "lint" {
+        & ruff check .
+    }
+    "lint:fix" {
+        & ruff check . --fix
+    }
     default {
         Write-Error "Command '$Command' not found."
     }

From 084d8f5ffe9aa8da81db71347a02f0a7d416127d Mon Sep 17 00:00:00 2001
From: Kevin Reed <kevin.a.reed@gmail.com>
Date: Mon, 7 Aug 2023 22:23:40 -0500
Subject: [PATCH 12/21] refactor

---
 .vscode/settings.json |  8 ++++++++
 Work/pcost_test.py    |  7 +++++--
 Work/report_test.py   | 22 +++++++++++++++-------
 Work/work.ps1         |  4 ++--
 4 files changed, 30 insertions(+), 11 deletions(-)
 create mode 100644 .vscode/settings.json

diff --git a/.vscode/settings.json b/.vscode/settings.json
new file mode 100644
index 000000000..ce3bda480
--- /dev/null
+++ b/.vscode/settings.json
@@ -0,0 +1,8 @@
+{
+    "python.testing.pytestArgs": [
+        "Work",
+        "--rootdir=Work",
+    ],
+    "python.testing.unittestEnabled": false,
+    "python.testing.pytestEnabled": true
+}
\ No newline at end of file
diff --git a/Work/pcost_test.py b/Work/pcost_test.py
index d679f38af..10286d468 100644
--- a/Work/pcost_test.py
+++ b/Work/pcost_test.py
@@ -1,7 +1,10 @@
 from pcost import pcost
+from os import path
+
+data_dir = path.join(path.dirname(__file__), 'Data')
 
 def test_pcost_1_27():
-    assert pcost('Data/portfolio.csv') == 44671.15
+    assert pcost(path.join(data_dir, 'portfolio.csv')) == 44671.15
 
 def test_pcost_1_31():
-    assert pcost('Data/missing.csv') == 27381.15
\ No newline at end of file
+    assert pcost(path.join(data_dir, 'missing.csv')) == 27381.15
\ No newline at end of file
diff --git a/Work/report_test.py b/Work/report_test.py
index 7508675bd..c25cdd307 100644
--- a/Work/report_test.py
+++ b/Work/report_test.py
@@ -1,7 +1,10 @@
+from os import path
 from report import read_portfolio, read_portfolio_2_5, read_prices_2_6, get_gainloss_2_7
 
+data_dir = path.join(path.dirname(__file__), 'Data')
+
 def test_read_portfolio_2_4():
-    portfolio = read_portfolio('Data/portfolio.csv')
+    portfolio = read_portfolio(path.join(data_dir, 'portfolio.csv'))
     assert portfolio == [
         ('AA', 100, 32.2),
         ('IBM', 50, 91.1),
@@ -13,21 +16,26 @@ def test_read_portfolio_2_4():
     ]
 
 def test_read_portfolio_2_5():
-    portfolio = read_portfolio_2_5('Data/portfolio.csv')
+    portfolio = read_portfolio_2_5(path.join(data_dir, 'portfolio.csv'))
     assert portfolio == [
-        {'name': 'AA', 'shares': 100, 'price': 32.2}, {'name': 'IBM', 'shares': 50, 'price': 91.1},
-        {'name': 'CAT', 'shares': 150, 'price': 83.44}, {'name': 'MSFT', 'shares': 200, 'price': 51.23},
-        {'name': 'GE', 'shares': 95, 'price': 40.37}, {'name': 'MSFT', 'shares': 50, 'price': 65.1},
+        {'name': 'AA', 'shares': 100, 'price': 32.2},
+        {'name': 'IBM', 'shares': 50, 'price': 91.1},
+        {'name': 'CAT', 'shares': 150, 'price': 83.44},
+        {'name': 'MSFT', 'shares': 200, 'price': 51.23},
+        {'name': 'GE', 'shares': 95, 'price': 40.37},
+        {'name': 'MSFT', 'shares': 50, 'price': 65.1},
         {'name': 'IBM', 'shares': 100, 'price': 70.44}
     ]
 
 def test_read_prices_2_6():
-    prices = read_prices_2_6('Data/prices.csv')
+    prices = read_prices_2_6(path.join(data_dir, 'prices.csv'))
     assert prices['AA'] == 9.22
     assert prices['AXP'] == 24.85
     assert prices['IBM'] == 106.28
     assert prices['MSFT'] == 20.89
 
 def test_get_gainloss_2_7():
-    gain_loss = get_gainloss_2_7('Data/portfolio.csv', 'Data/prices.csv')
+    gain_loss = get_gainloss_2_7(
+        path.join(data_dir, 'portfolio.csv'),
+        path.join(data_dir, 'prices.csv'))
     assert round(gain_loss, 2) == -15985.05
\ No newline at end of file
diff --git a/Work/work.ps1 b/Work/work.ps1
index a74ccfb21..d7a38c3d2 100644
--- a/Work/work.ps1
+++ b/Work/work.ps1
@@ -2,8 +2,8 @@ param([string]$Command)
 
 switch ($Command) {
     "venv" {
-        & python -m venv venv
-        & $PSScriptRoot\venv\Scripts\Activate.ps1
+        & python -m venv .venv
+        & $PSScriptRoot\.venv\Scripts\Activate.ps1
         & pip install -r $PSScriptRoot\requirements.txt
     }
     "test" {

From 3a7839ad6e71b9907534861bc32ecbad468522cf Mon Sep 17 00:00:00 2001
From: Kevin Reed <kevin.a.reed@gmail.com>
Date: Mon, 7 Aug 2023 23:26:54 -0500
Subject: [PATCH 13/21] 2.12

---
 Work/currency.py       |  4 ++++
 Work/currency_test.py  | 13 +++++++++++++
 Work/report.py         | 35 ++++++++++++++++++++++++-----------
 Work/report_command.py |  8 ++++++++
 Work/report_test.py    |  2 +-
 5 files changed, 50 insertions(+), 12 deletions(-)
 create mode 100644 Work/currency.py
 create mode 100644 Work/currency_test.py
 create mode 100644 Work/report_command.py

diff --git a/Work/currency.py b/Work/currency.py
new file mode 100644
index 000000000..6ffee15ab
--- /dev/null
+++ b/Work/currency.py
@@ -0,0 +1,4 @@
+def usd(value: float) -> str:
+    """Format a number as USD."""
+    neg = '-' if value < 0 else ''
+    return f"{neg}${abs(value):,.2f}"
\ No newline at end of file
diff --git a/Work/currency_test.py b/Work/currency_test.py
new file mode 100644
index 000000000..98139a348
--- /dev/null
+++ b/Work/currency_test.py
@@ -0,0 +1,13 @@
+import pytest
+from currency import usd
+
+@pytest.mark.parametrize("input,output", [
+    (1, "$1.00"),
+    (11.5, "$11.50"),
+    (1.75, "$1.75"),
+    (1200.751, "$1,200.75"),
+    (-1245.758, "-$1,245.76"),
+    (-1.754, "-$1.75")
+])
+def test_usd(input, output):
+    assert usd(input) == output
\ No newline at end of file
diff --git a/Work/report.py b/Work/report.py
index 0e89a5355..94a903473 100644
--- a/Work/report.py
+++ b/Work/report.py
@@ -2,7 +2,7 @@
 #
 # Exercise 2.4
 import csv
-from pprint import pprint
+from currency import usd
 
 def read_portfolio(filename):
     portfolio = []
@@ -48,7 +48,7 @@ def read_prices_2_6(filename):
             except ValueError:
                 print(f'Could not parse {row}')
 
-    pprint(prices)
+    # pprint(prices)
     return prices
 
 def get_gainloss_2_7(stocksFilename, pricesFilename):
@@ -57,20 +57,33 @@ def get_gainloss_2_7(stocksFilename, pricesFilename):
 
     total_value = 0.0
     total_market_value = 0.0
-    total_gain_loss = 0.0
+    total_gain = 0.0
+
     for stock in stocks:
+        market_price = prices[stock['name']]
+        stock['change'] = market_price - stock['price']
         stock['current_value'] = stock['price'] * stock['shares']
-        stock['market_value'] = prices[stock['name']] * stock['shares']
-        stock['gain_loss'] = stock['market_value'] - stock['current_value']
+        stock['market_value'] = market_price * stock['shares']
+        stock['value_gain'] = stock['market_value'] - stock['current_value']
 
         total_value += stock['current_value']
         total_market_value += stock['market_value']
-        total_gain_loss += stock['gain_loss']
+        total_gain += stock['value_gain']
+
+    return (total_gain, stocks)
 
-        print('{name:s} {gain_loss:,.2f}'.format_map(stock))
+def make_report_2_9(
+    stocksFilename,
+    pricesFilename):
+    
+    (_, stocks) = get_gainloss_2_7(
+        stocksFilename,
+        pricesFilename)
 
-    print(f'Total value: {total_value:,.2f}')
-    print(f'Total market value: {total_market_value:,.2f}')
-    print(f'Total gain/loss: {total_gain_loss:,.2f}')
+    print()
+    print(' '.join([f'{h:>10s}' for h in ['Name', 'Shares', 'Price', 'Change']]))
+    print(' '.join(['----------' for _ in range(4)]))
 
-    return total_gain_loss
\ No newline at end of file
+    for stock in stocks:
+        (name, shares, price, change, _, _, _) = stock.values()
+        print(f'{name:>10s} {shares:>10d} {usd(price):>10s} {usd(change):>10s}')
\ No newline at end of file
diff --git a/Work/report_command.py b/Work/report_command.py
new file mode 100644
index 000000000..8c7fae4ba
--- /dev/null
+++ b/Work/report_command.py
@@ -0,0 +1,8 @@
+from os import path
+from report import make_report_2_9
+
+data_dir = path.join(path.dirname(__file__), 'Data')
+
+make_report_2_9(
+    path.join(data_dir, 'portfolio.csv'),
+    path.join(data_dir, 'prices.csv'))
\ No newline at end of file
diff --git a/Work/report_test.py b/Work/report_test.py
index c25cdd307..3a8a22058 100644
--- a/Work/report_test.py
+++ b/Work/report_test.py
@@ -35,7 +35,7 @@ def test_read_prices_2_6():
     assert prices['MSFT'] == 20.89
 
 def test_get_gainloss_2_7():
-    gain_loss = get_gainloss_2_7(
+    (gain_loss, _) = get_gainloss_2_7(
         path.join(data_dir, 'portfolio.csv'),
         path.join(data_dir, 'prices.csv'))
     assert round(gain_loss, 2) == -15985.05
\ No newline at end of file

From 782eb58ad3981ed9d3db171b481a6cacda58673a Mon Sep 17 00:00:00 2001
From: Kevin Reed <kevin.a.reed@gmail.com>
Date: Mon, 14 Aug 2023 22:21:21 -0500
Subject: [PATCH 14/21] 2.15

---
 Work/pcost.py | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/Work/pcost.py b/Work/pcost.py
index ba4d0032f..d772579b1 100644
--- a/Work/pcost.py
+++ b/Work/pcost.py
@@ -7,13 +7,12 @@ def pcost(filename):
     '''Returns the total cost of the portfolio'''
     with open(filename, 'rt') as f:
         rows = csv.reader(f)
-        next(rows) # skip header
         cost = 0.0
-        for fields in rows:
+        for line_no, row in enumerate(rows, start=1):
             try:
-                shares = int(fields[1])
-                stock_cost = float(fields[2])
+                shares = int(row[1])
+                stock_cost = float(row[2])
                 cost += shares * stock_cost
             except ValueError:
-                print(f'Could not parse {fields}')
+                print(f'Could not parse line {line_no} with data: {row}')
     return cost
\ No newline at end of file

From 881b0bb893a157d767c3de7b6a1d532aabbe906f Mon Sep 17 00:00:00 2001
From: Kevin Reed <kevin.a.reed@gmail.com>
Date: Mon, 14 Aug 2023 22:35:27 -0500
Subject: [PATCH 15/21] 2.16

---
 Work/pcost.py       | 15 +++++++++------
 Work/pcost_test.py  |  5 ++++-
 Work/report.py      | 15 ++++++++-------
 Work/report_test.py | 10 ++++++++--
 4 files changed, 29 insertions(+), 16 deletions(-)

diff --git a/Work/pcost.py b/Work/pcost.py
index d772579b1..d9f5dfb04 100644
--- a/Work/pcost.py
+++ b/Work/pcost.py
@@ -6,13 +6,16 @@
 def pcost(filename):
     '''Returns the total cost of the portfolio'''
     with open(filename, 'rt') as f:
-        rows = csv.reader(f)
+        lines = csv.reader(f)
         cost = 0.0
-        for line_no, row in enumerate(rows, start=1):
+        header_line = next(lines)
+        print(header_line)
+        for line_no, line in enumerate(lines):
+            record = dict(zip(header_line, line))
             try:
-                shares = int(row[1])
-                stock_cost = float(row[2])
-                cost += shares * stock_cost
+                shares = int(record['shares'])
+                price = float(record['price'])
+                cost += shares * price
             except ValueError:
-                print(f'Could not parse line {line_no} with data: {row}')
+                print(f'Could not parse line {line_no} with data: {line}')
     return cost
\ No newline at end of file
diff --git a/Work/pcost_test.py b/Work/pcost_test.py
index 10286d468..e9effb416 100644
--- a/Work/pcost_test.py
+++ b/Work/pcost_test.py
@@ -7,4 +7,7 @@ def test_pcost_1_27():
     assert pcost(path.join(data_dir, 'portfolio.csv')) == 44671.15
 
 def test_pcost_1_31():
-    assert pcost(path.join(data_dir, 'missing.csv')) == 27381.15
\ No newline at end of file
+    assert pcost(path.join(data_dir, 'missing.csv')) == 27381.15
+
+def test_pcost_2_16():
+    assert pcost(path.join(data_dir, 'portfoliodate.csv')) == 44671.15
\ No newline at end of file
diff --git a/Work/report.py b/Work/report.py
index 94a903473..d7c98b78a 100644
--- a/Work/report.py
+++ b/Work/report.py
@@ -4,7 +4,7 @@
 import csv
 from currency import usd
 
-def read_portfolio(filename):
+def read_portfolio_2_4(filename):
     portfolio = []
     with open(filename, 'rt') as f:
         rows = csv.reader(f)
@@ -21,17 +21,18 @@ def read_portfolio_2_5(filename):
     portfolio = []
     with open(filename, 'rt') as f:
         rows = csv.reader(f)
-        next(rows) # skip header
-        for fields in rows:
+        header = next(rows) # skip header
+        for row_no, fields in enumerate(rows):
             try:
+                record = dict(zip(header, fields))
                 holding = {
-                    'name': fields[0],
-                    'shares': int(fields[1]),
-                    'price': float(fields[2])
+                    'name': record['name'],
+                    'shares': int(record['shares']),
+                    'price': float(record['price'])
                 }
                 portfolio.append(holding)
             except ValueError:
-                print(f'Could not parse {fields}')
+                print(f'Could not parse row {row_no} with data {fields}')
     return portfolio
 
 def read_prices_2_6(filename):
diff --git a/Work/report_test.py b/Work/report_test.py
index 3a8a22058..968b4e8bd 100644
--- a/Work/report_test.py
+++ b/Work/report_test.py
@@ -1,10 +1,10 @@
 from os import path
-from report import read_portfolio, read_portfolio_2_5, read_prices_2_6, get_gainloss_2_7
+from report import read_portfolio_2_4, read_portfolio_2_5, read_prices_2_6, get_gainloss_2_7
 
 data_dir = path.join(path.dirname(__file__), 'Data')
 
 def test_read_portfolio_2_4():
-    portfolio = read_portfolio(path.join(data_dir, 'portfolio.csv'))
+    portfolio = read_portfolio_2_4(path.join(data_dir, 'portfolio.csv'))
     assert portfolio == [
         ('AA', 100, 32.2),
         ('IBM', 50, 91.1),
@@ -38,4 +38,10 @@ def test_get_gainloss_2_7():
     (gain_loss, _) = get_gainloss_2_7(
         path.join(data_dir, 'portfolio.csv'),
         path.join(data_dir, 'prices.csv'))
+    assert round(gain_loss, 2) == -15985.05
+
+def test_report_2_16():
+    (gain_loss, _) = get_gainloss_2_7(
+        path.join(data_dir, 'portfoliodate.csv'),
+        path.join(data_dir, 'prices.csv'))
     assert round(gain_loss, 2) == -15985.05
\ No newline at end of file

From 1736c36a104f2644f018653f0ae19a7ffcc5a55f Mon Sep 17 00:00:00 2001
From: Kevin Reed <kevin.a.reed@gmail.com>
Date: Mon, 14 Aug 2023 23:32:36 -0500
Subject: [PATCH 16/21] 2.26

---
 Work/dowstocks.py | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 Work/dowstocks.py

diff --git a/Work/dowstocks.py b/Work/dowstocks.py
new file mode 100644
index 000000000..86c76cd47
--- /dev/null
+++ b/Work/dowstocks.py
@@ -0,0 +1,20 @@
+import csv
+
+def date_tuple(s):
+    return tuple(str(s).split('/'))
+
+def main():
+    with open('Data/dowstocks.csv') as f:
+        rows = csv.reader(f)
+        headers = next(rows)
+        print(headers)
+        types = [str, float, date_tuple, str, float, float, float, float, int]
+        dow_stocks = [
+            { key: func(val) for key, func, val in zip(headers, types, row) }
+            for row in rows
+        ]
+        print(dow_stocks[0]['date'])
+        print(len(dow_stocks))
+
+if __name__ == '__main__':
+    main()
\ No newline at end of file

From adaefca46453755ae6a6f8073557ac74f3db194a Mon Sep 17 00:00:00 2001
From: Kevin Reed <kevin.a.reed@gmail.com>
Date: Tue, 15 Aug 2023 23:06:03 -0500
Subject: [PATCH 17/21] 3.4

---
 Work/fileparse.py      | 27 +++++++++++++++++++++++++++
 Work/fileparse_test.py |  8 ++++++++
 2 files changed, 35 insertions(+)
 create mode 100644 Work/fileparse_test.py

diff --git a/Work/fileparse.py b/Work/fileparse.py
index 1d499e733..bd095465c 100644
--- a/Work/fileparse.py
+++ b/Work/fileparse.py
@@ -1,3 +1,30 @@
 # fileparse.py
 #
 # Exercise 3.3
+
+import csv
+
+def parse_csv(filename, select: list):
+    '''
+    Parse a CSV file into a list of records
+    '''
+    with open(filename) as f:
+        rows = csv.reader(f)
+
+        # Read the file headers
+        headers = next(rows)
+        select_indices = [headers.index(name) for name in select] \
+            if select \
+            else [i for i in range(len(headers))]
+        if select:
+            headers = select
+        records = []
+        for row in rows:
+            if not row:    # Skip rows with no data
+                continue
+            record = dict(zip(
+                headers,
+                [row[i] for i in select_indices]))
+            records.append(record)
+
+    return records
\ No newline at end of file
diff --git a/Work/fileparse_test.py b/Work/fileparse_test.py
new file mode 100644
index 000000000..abc67f501
--- /dev/null
+++ b/Work/fileparse_test.py
@@ -0,0 +1,8 @@
+from fileparse import parse_csv
+
+def test_parse_csv_select_3_4():
+    assert parse_csv('Data/portfolio.csv', select=['name','shares']) == \
+        [{'name': 'AA', 'shares': '100'}, {'name': 'IBM', 'shares': '50'},
+         {'name': 'CAT', 'shares': '150'}, {'name': 'MSFT', 'shares': '200'},
+         {'name': 'GE', 'shares': '95'}, {'name': 'MSFT', 'shares': '50'},
+         {'name': 'IBM', 'shares': '100'}]

From 8b8f323c080948a9bd4d393d760fabee34cab1cd Mon Sep 17 00:00:00 2001
From: Kevin Reed <kevin.a.reed@gmail.com>
Date: Tue, 15 Aug 2023 23:23:11 -0500
Subject: [PATCH 18/21] 3.5

---
 .vscode/settings.json  |  6 +++++-
 Work/fileparse.py      | 29 ++++++++++++++++-------------
 Work/fileparse_test.py | 39 ++++++++++++++++++++++++++++++++++-----
 3 files changed, 55 insertions(+), 19 deletions(-)

diff --git a/.vscode/settings.json b/.vscode/settings.json
index ce3bda480..dafd670c2 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -4,5 +4,9 @@
         "--rootdir=Work",
     ],
     "python.testing.unittestEnabled": false,
-    "python.testing.pytestEnabled": true
+    "python.testing.pytestEnabled": true,
+    "[python]": {
+        "editor.defaultFormatter": "ms-python.black-formatter"
+    },
+    "python.formatting.provider": "none"
 }
\ No newline at end of file
diff --git a/Work/fileparse.py b/Work/fileparse.py
index bd095465c..cd76dc1ad 100644
--- a/Work/fileparse.py
+++ b/Work/fileparse.py
@@ -4,27 +4,30 @@
 
 import csv
 
-def parse_csv(filename, select: list):
-    '''
+
+def parse_csv(filename, select: list = [], types: list = []):
+    """
     Parse a CSV file into a list of records
-    '''
+    """
     with open(filename) as f:
         rows = csv.reader(f)
 
         # Read the file headers
-        headers = next(rows)
-        select_indices = [headers.index(name) for name in select] \
-            if select \
+        file_headers = next(rows)
+        headers = select if select else file_headers
+        indices = (
+            [headers.index(name) for name in select]
+            if select
             else [i for i in range(len(headers))]
-        if select:
-            headers = select
+        )
         records = []
         for row in rows:
-            if not row:    # Skip rows with no data
+            if not row:  # Skip rows with no data
                 continue
-            record = dict(zip(
-                headers,
-                [row[i] for i in select_indices]))
+            select_row = [row[col] for col in indices]
+            if types:
+                select_row = [func(col) for func, col in zip(types, select_row)]
+            record = dict(zip(headers, select_row))
             records.append(record)
 
-    return records
\ No newline at end of file
+    return records
diff --git a/Work/fileparse_test.py b/Work/fileparse_test.py
index abc67f501..1e8d5b475 100644
--- a/Work/fileparse_test.py
+++ b/Work/fileparse_test.py
@@ -1,8 +1,37 @@
 from fileparse import parse_csv
 
+
 def test_parse_csv_select_3_4():
-    assert parse_csv('Data/portfolio.csv', select=['name','shares']) == \
-        [{'name': 'AA', 'shares': '100'}, {'name': 'IBM', 'shares': '50'},
-         {'name': 'CAT', 'shares': '150'}, {'name': 'MSFT', 'shares': '200'},
-         {'name': 'GE', 'shares': '95'}, {'name': 'MSFT', 'shares': '50'},
-         {'name': 'IBM', 'shares': '100'}]
+    assert parse_csv("Data/portfolio.csv", select=["name", "shares"]) == [
+        {"name": "AA", "shares": "100"},
+        {"name": "IBM", "shares": "50"},
+        {"name": "CAT", "shares": "150"},
+        {"name": "MSFT", "shares": "200"},
+        {"name": "GE", "shares": "95"},
+        {"name": "MSFT", "shares": "50"},
+        {"name": "IBM", "shares": "100"},
+    ]
+
+
+def test_parse_csv_select_3_5():
+    assert parse_csv("Data/portfolio.csv", types=[str, int, float]) == [
+        {"price": 32.2, "name": "AA", "shares": 100},
+        {"price": 91.1, "name": "IBM", "shares": 50},
+        {"price": 83.44, "name": "CAT", "shares": 150},
+        {"price": 51.23, "name": "MSFT", "shares": 200},
+        {"price": 40.37, "name": "GE", "shares": 95},
+        {"price": 65.1, "name": "MSFT", "shares": 50},
+        {"price": 70.44, "name": "IBM", "shares": 100},
+    ]
+
+    assert parse_csv(
+        "Data/portfolio.csv", select=["name", "shares"], types=[str, int]
+    ) == [
+        {"name": "AA", "shares": 100},
+        {"name": "IBM", "shares": 50},
+        {"name": "CAT", "shares": 150},
+        {"name": "MSFT", "shares": 200},
+        {"name": "GE", "shares": 95},
+        {"name": "MSFT", "shares": 50},
+        {"name": "IBM", "shares": 100},
+    ]

From ab9a1263a14f1570df4ef91558ea7c98985989a5 Mon Sep 17 00:00:00 2001
From: Kevin Reed <kevin.a.reed@gmail.com>
Date: Tue, 15 Aug 2023 23:32:56 -0500
Subject: [PATCH 19/21] 3.6

---
 Work/fileparse.py      | 29 ++++++++++++-----------------
 Work/fileparse_test.py | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+), 17 deletions(-)

diff --git a/Work/fileparse.py b/Work/fileparse.py
index cd76dc1ad..317db9e75 100644
--- a/Work/fileparse.py
+++ b/Work/fileparse.py
@@ -1,33 +1,28 @@
 # fileparse.py
 #
 # Exercise 3.3
-
 import csv
 
 
-def parse_csv(filename, select: list = [], types: list = []):
+def parse_csv(
+    filename: str, select: list = [], types: list = [], has_headers: bool = True
+) -> list:
     """
     Parse a CSV file into a list of records
     """
     with open(filename) as f:
         rows = csv.reader(f)
-
-        # Read the file headers
-        file_headers = next(rows)
-        headers = select if select else file_headers
-        indices = (
-            [headers.index(name) for name in select]
-            if select
-            else [i for i in range(len(headers))]
-        )
+        if has_headers:
+            orig_headers = next(rows)
+            headers = select if select else orig_headers
+            indices = [headers.index(name) for name in headers]
         records = []
-        for row in rows:
-            if not row:  # Skip rows with no data
+        for orig_row in rows:
+            if not orig_row:
                 continue
-            select_row = [row[col] for col in indices]
+            row = [orig_row[i] for i in indices] if has_headers else orig_row
             if types:
-                select_row = [func(col) for func, col in zip(types, select_row)]
-            record = dict(zip(headers, select_row))
+                row = [func(field) for func, field in zip(types, row)]
+            record = dict(zip(headers, row)) if has_headers else tuple(row)
             records.append(record)
-
     return records
diff --git a/Work/fileparse_test.py b/Work/fileparse_test.py
index 1e8d5b475..7cb92a27f 100644
--- a/Work/fileparse_test.py
+++ b/Work/fileparse_test.py
@@ -35,3 +35,38 @@ def test_parse_csv_select_3_5():
         {"name": "MSFT", "shares": 50},
         {"name": "IBM", "shares": 100},
     ]
+
+
+def test_parse_csv_no_headers_3_6():
+    assert parse_csv("Data/prices.csv", types=[str, float], has_headers=False) == [
+        ("AA", 9.22),
+        ("AXP", 24.85),
+        ("BA", 44.85),
+        ("BAC", 11.27),
+        ("C", 3.72),
+        ("CAT", 35.46),
+        ("CVX", 66.67),
+        ("DD", 28.47),
+        ("DIS", 24.22),
+        ("GE", 13.48),
+        ("GM", 0.75),
+        ("HD", 23.16),
+        ("HPQ", 34.35),
+        ("IBM", 106.28),
+        ("INTC", 15.72),
+        ("JNJ", 55.16),
+        ("JPM", 36.9),
+        ("KFT", 26.11),
+        ("KO", 49.16),
+        ("MCD", 58.99),
+        ("MMM", 57.1),
+        ("MRK", 27.58),
+        ("MSFT", 20.89),
+        ("PFE", 15.19),
+        ("PG", 51.94),
+        ("T", 24.79),
+        ("UTX", 52.61),
+        ("VZ", 29.26),
+        ("WMT", 49.74),
+        ("XOM", 69.35),
+    ]

From 47368e9d37614419411d01ca906d9c9e6d7fabae Mon Sep 17 00:00:00 2001
From: Kevin Reed <kevin.a.reed@gmail.com>
Date: Tue, 15 Aug 2023 23:45:58 -0500
Subject: [PATCH 20/21] 3.7

---
 Work/fileparse.py      |  8 ++++++--
 Work/fileparse_test.py | 12 ++++++++++++
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/Work/fileparse.py b/Work/fileparse.py
index 317db9e75..0e35f5b00 100644
--- a/Work/fileparse.py
+++ b/Work/fileparse.py
@@ -5,13 +5,17 @@
 
 
 def parse_csv(
-    filename: str, select: list = [], types: list = [], has_headers: bool = True
+    filename: str,
+    select: list = [],
+    types: list = [],
+    has_headers: bool = True,
+    delimiter: str = ",",
 ) -> list:
     """
     Parse a CSV file into a list of records
     """
     with open(filename) as f:
-        rows = csv.reader(f)
+        rows = csv.reader(f, delimiter=delimiter)
         if has_headers:
             orig_headers = next(rows)
             headers = select if select else orig_headers
diff --git a/Work/fileparse_test.py b/Work/fileparse_test.py
index 7cb92a27f..0fe4e8a0d 100644
--- a/Work/fileparse_test.py
+++ b/Work/fileparse_test.py
@@ -70,3 +70,15 @@ def test_parse_csv_no_headers_3_6():
         ("WMT", 49.74),
         ("XOM", 69.35),
     ]
+
+
+def test_parse_csv_delimiter_3_7():
+    assert parse_csv("Data/portfolio.dat", types=[str, int, float], delimiter=" ") == [
+        { "name": "AA", "shares": 100, "price": 32.2 },
+        { "name": "IBM", "shares": 50, "price": 91.1 },
+        { "name": "CAT", "shares": 150, "price": 83.44 },
+        { "name": "MSFT", "shares": 200, "price": 51.23 },
+        { "name": "GE", "shares": 95, "price": 40.37 },
+        { "name": "MSFT", "shares": 50, "price": 65.1 },
+        { "name": "IBM", "shares": 100, "price": 70.44 },
+    ]

From 1ac115a7f3e823006f12d25019c1a99613f583b8 Mon Sep 17 00:00:00 2001
From: Kevin Reed <kevin.a.reed@gmail.com>
Date: Tue, 15 Aug 2023 23:44:25 -0500
Subject: [PATCH 21/21] Output correct types in example

---
 Notes/03_Program_organization/02_More_functions.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Notes/03_Program_organization/02_More_functions.md b/Notes/03_Program_organization/02_More_functions.md
index 579a4b980..2c47872b7 100644
--- a/Notes/03_Program_organization/02_More_functions.md
+++ b/Notes/03_Program_organization/02_More_functions.md
@@ -501,7 +501,7 @@ For example:
 ```python
 >>> portfolio = parse_csv('Data/portfolio.dat', types=[str, int, float], delimiter=' ')
 >>> portfolio
-[{'price': '32.20', 'name': 'AA', 'shares': '100'}, {'price': '91.10', 'name': 'IBM', 'shares': '50'}, {'price': '83.44', 'name': 'CAT', 'shares': '150'}, {'price': '51.23', 'name': 'MSFT', 'shares': '200'}, {'price': '40.37', 'name': 'GE', 'shares': '95'}, {'price': '65.10', 'name': 'MSFT', 'shares': '50'}, {'price': '70.44', 'name': 'IBM', 'shares': '100'}]
+[{'name': 'AA', 'shares': 100, 'price': 32.2}, {'name': 'IBM', 'shares': 50, 'price': 91.1}, {'name': 'CAT', 'shares': 150, 'price': 83.44}, {'name': 'MSFT', 'shares': 200, 'price': 51.23}, {'name': 'GE', 'shares': 95, 'price': 40.37}, {'name': 'MSFT', 'shares': 50, 'price': 65.1}, {'name': 'IBM', 'shares': 100, 'price': 70.44}]
 >>>
 ```