diff --git a/.gitignore b/.gitignore
index b6e47617d..4b492eb54 100644
--- a/.gitignore
+++ b/.gitignore
@@ -127,3 +127,6 @@ dmypy.json
 
 # Pyre type checker
 .pyre/
+
+# PyCharm
+.idea
\ No newline at end of file
diff --git a/Work/bounce.py b/Work/bounce.py
index 3660ddd82..a0c5bab84 100644
--- a/Work/bounce.py
+++ b/Work/bounce.py
@@ -1,3 +1,12 @@
 # bounce.py
 #
 # Exercise 1.5
+
+height = 100
+bounce = 0
+
+while bounce < 10:
+    height = height * (3 / 5)
+    bounce = bounce + 1
+    roundedHeight = round(height * 10000) / 10000
+    print(bounce, roundedHeight)
diff --git a/Work/fileparse.py b/Work/fileparse.py
index 1d499e733..ec992aa42 100644
--- a/Work/fileparse.py
+++ b/Work/fileparse.py
@@ -1,3 +1,67 @@
 # fileparse.py
 #
 # Exercise 3.3
+
+import csv
+from pprint import pprint
+
+
+def parse_csv(lines, select=None, types=None, has_headers=True, silence_errors=True, delimiter=','):
+    """
+    Parse a CSV file into a list of records
+    """
+    if not has_headers and select:
+        raise RuntimeError("wrong combination of args")
+
+    rows = csv.reader(lines, delimiter=delimiter)
+
+    # Read the file headers
+    if has_headers:
+        headers = next(rows)
+    else:
+        headers = None
+
+    # If a column selector was given, find indices of the specified columns.
+    # Also narrow the set of headers used for resulting dictionaries
+    if select:
+        indices = [headers.index(colname) for colname in select]
+        headers = select
+    else:
+        indices = []
+
+    records = []
+    for index, row in enumerate(rows):
+        try:
+            if not row:  # Skip rows with no data
+                continue
+
+            # Filter the row if specific columns were selected
+            if indices:
+                row = [row[index] for index in indices]
+
+            if types:
+                row = [func(val) for func, val in zip(types, row)]
+
+            if headers:
+                record = dict(zip(headers, row))
+            else:
+                record = tuple(row)
+
+            records.append(record)
+        except ValueError as e:
+            if not silence_errors:
+                print(f"Row {index + 1}: Couldn't convert", row)
+                print(f"Row {index + 1}: Reason", e)
+            pass
+
+    return records
+
+
+def main():
+    with open('Data/portfolio.csv', 'rt') as f:
+        portfolio = parse_csv(f, types=[str, int, float], silence_errors=False)
+        pprint(portfolio)
+
+
+if __name__ == '__main__':
+    main()
diff --git a/Work/files.py b/Work/files.py
new file mode 100644
index 000000000..1902d5c9a
--- /dev/null
+++ b/Work/files.py
@@ -0,0 +1,8 @@
+# with open("Data/portfolio.csv", "rt") as f:
+#     for line in f:
+#         print(line, end="")
+
+import gzip
+with gzip.open("Data/portfolio.csv.gz", "rt") as f:
+    for line in f:
+        print(line, end="")
diff --git a/Work/generators.py b/Work/generators.py
new file mode 100644
index 000000000..9e556e95f
--- /dev/null
+++ b/Work/generators.py
@@ -0,0 +1,27 @@
+from random import random
+from time import sleep
+
+
+def generate_number():
+    while True:
+        sleep(0.5)
+        yield random()
+
+
+def filter_numbers(numbers):
+    for n in numbers:
+        if n > 0.5:
+            yield n
+
+# Generator expression variant:
+# def filter_numbers(numbers):
+#     return (x for x in numbers if x > 0.5)
+
+
+n = generate_number()
+f = filter_numbers(n)
+for i, n in enumerate(f):
+    if i > 10:
+        break
+    else:
+        print(f"{i:>2}: {n}")
diff --git a/Work/lists.py b/Work/lists.py
new file mode 100644
index 000000000..a2470ef5f
--- /dev/null
+++ b/Work/lists.py
@@ -0,0 +1,17 @@
+# lists.py
+# Exercise 1.2x
+
+mylist = ["a", "b", "c"]
+if "x" not in mylist:
+    print("Yo")
+
+mylist.append("bla")
+mylist.sort(reverse=True)
+
+print(",".join(mylist))
+
+nums = [101, 102, 103]
+items = ["spam", mylist, nums]
+print(items)
+print(items[1][-1])
+print(items[0][-1])
diff --git a/Work/mortgage.py b/Work/mortgage.py
index d527314e3..1469429fe 100644
--- a/Work/mortgage.py
+++ b/Work/mortgage.py
@@ -1,3 +1,31 @@
 # mortgage.py
 #
 # Exercise 1.7
+
+extra_payment_start_month = 61
+extra_payment_end_month = 108
+extra_payment = 1000
+
+principal = 500000.0
+rate = 0.05
+payment = 2684.11
+total_paid = 0.0
+month = 0
+
+while principal > 0:
+    month = month + 1
+    if extra_payment_start_month <= month <= extra_payment_end_month:
+        monthly_extra = extra_payment
+    else:
+        monthly_extra = 0
+
+    principal = principal * (1 + rate / 12) - payment - monthly_extra
+    total_paid = total_paid + payment + monthly_extra
+    if principal < 0:
+        total_paid = total_paid - abs(principal)
+        principal = 0
+
+    print(f'{month:3}  {total_paid:9.2f}  {principal:9.2f}')
+
+total_paid_formatted = '{:,}'.format(round(total_paid, 2))
+print(f'\nTotal paid {total_paid_formatted} over {month} months')
diff --git a/Work/pcost.py b/Work/pcost.py
index e68aa20b4..42955c71a 100644
--- a/Work/pcost.py
+++ b/Work/pcost.py
@@ -1,3 +1,20 @@
 # pcost.py
 #
 # Exercise 1.27
+
+import sys
+from Work.fileparse import parse_csv
+
+
+def portfolio_cost(filename):
+    with open(filename, "rt") as f:
+        return parse_csv(f, select=["shares", "price"], types=[int, float], silence_errors=True)
+
+
+if len(sys.argv) == 2:
+    filename = sys.argv[1]
+else:
+    filename = "Data/portfolio.csv"
+
+cost = portfolio_cost(filename)
+print("Total cost:", cost)
diff --git a/Work/report.py b/Work/report.py
index 47d5da7b1..f27f21d8b 100644
--- a/Work/report.py
+++ b/Work/report.py
@@ -1,3 +1,74 @@
+#!/usr/bin/env python3
 # report.py
 #
 # Exercise 2.4
+from pprint import pprint
+
+from Work import tableformat
+from Work.fileparse import parse_csv
+from Work.stock import Stock
+
+
+def read_portfolio(filename):
+    with open(filename, "rt") as f:
+        dicts = parse_csv(f, types=[str, int, float])
+        return [Stock(**p) for p in dicts]
+
+
+def read_prices(filename):
+    with open(filename, "rt") as f:
+        prices = parse_csv(f, types=[str, float], has_headers=False, silence_errors=True)
+        return dict(prices)
+
+
+def make_report(portfolio, prices):
+    rows = []
+    for p in portfolio:
+        name = p.name
+        shares = p.shares
+        price = p.price
+        current_price = prices[name]
+        change = current_price - price
+        rows.append((name, shares, current_price, change))
+    return rows
+
+
+def print_report(reportdata, formatter):
+    """
+    Print a nicely formated table from a list of (name, shares, price, change) tuples.
+    """
+    formatter.headings(['Name', 'Shares', 'Price', 'Change'])
+    for name, shares, price, change in reportdata:
+        rowdata = [name, str(shares), f'{price:0.2f}', f'{change:0.2f}']
+        formatter.row(rowdata)
+
+
+def portfolio_report(portfoliofile, pricefile, fmt='txt'):
+    """
+    Make a stock report given portfolio and price data files.
+    """
+    # Read data files
+    portfolio = read_portfolio(portfoliofile)
+    prices = read_prices(pricefile)
+
+    # Create the report data
+    report = make_report(portfolio, prices)
+
+    # Print it out
+    formatter = tableformat.create_formatter(fmt)
+    print_report(report, formatter)
+
+
+def main(argv):
+    portfolio = read_portfolio('Data/portfolio.csv')
+    portfolio.sort(key=lambda s: s.shares)
+    pprint(portfolio)
+
+    # portfolio_report('Data/portfolio.csv', 'Data/prices.csv')
+    # portfolio_report(argv[0], argv[1])
+
+
+if __name__ == '__main__':
+    import sys
+
+    main(sys.argv)
diff --git a/Work/sears.py b/Work/sears.py
new file mode 100644
index 000000000..8add59254
--- /dev/null
+++ b/Work/sears.py
@@ -0,0 +1,15 @@
+# sears.py
+
+bill_thickness = 0.11 * 0.001    # Meters (0.11 mm)
+sears_height   = 442             # Height (meters)
+num_bills      = 1
+day            = 1
+
+while num_bills * bill_thickness < sears_height:
+    print(day, num_bills, num_bills * bill_thickness)
+    day = day + 1
+    num_bills = num_bills * 2
+
+print('Number of days', day)
+print('Number of bills', num_bills)
+print('Final height', num_bills * bill_thickness)
\ No newline at end of file
diff --git a/Work/stock.py b/Work/stock.py
new file mode 100644
index 000000000..cb46d74df
--- /dev/null
+++ b/Work/stock.py
@@ -0,0 +1,36 @@
+from Work.typedproperty import StringProp, IntProp, FloatProp
+
+
+class Stock:
+    name = StringProp('name')
+    shares = IntProp('shares')
+    price = FloatProp('price')
+
+    def __init__(self, name: str, shares: int, price: float):
+        self.name = name
+        self.shares = shares
+        self.price = price
+
+    @property
+    def cost(self) -> float:
+        return self.shares * self.price
+
+    def sell(self, amount: int):
+        self.shares = max(self.shares - amount, 0)
+
+    def __repr__(self):
+        return f"Stock('{self.name}', {self.shares}, {self.price})"
+
+
+def main():
+    s = Stock("bla", 100, 9.9)
+    print(s)
+    with open("Data/portfolio.csv", "rt") as lines:
+        from Work.fileparse import parse_csv
+        portdicts = parse_csv(lines, select=['name', 'shares', 'price'], types=[str, int, float])
+        portfolio = [Stock(p["name"], p["shares"], p["price"]) for p in portdicts]
+        print(sum([s.cost for s in portfolio]))
+
+
+if __name__ == "__main__":
+    main()
diff --git a/Work/tableformat.py b/Work/tableformat.py
new file mode 100644
index 000000000..8ce2450c8
--- /dev/null
+++ b/Work/tableformat.py
@@ -0,0 +1,68 @@
+class TableFormatter:
+    def headings(self, headers):
+        """
+        Emit the table headings.
+        """
+        raise NotImplementedError()
+
+    def row(self, rowdata):
+        """
+        Emit a single row of table data.
+        """
+        raise NotImplementedError()
+
+
+class TextTableFormatter(TableFormatter):
+    """
+    Emit a table in plain-text format
+    """
+
+    def headings(self, headers):
+        for h in headers:
+            print(f'{h:>10s}', end=' ')
+        print()
+        print(('-' * 10 + ' ') * len(headers))
+
+    def row(self, rowdata):
+        for d in rowdata:
+            print(f'{d:>10s}', end=' ')
+        print()
+
+
+class CSVTableFormatter(TableFormatter):
+    """
+    Output portfolio data in CSV format.
+    """
+
+    def headings(self, headers):
+        print(','.join(headers))
+
+    def row(self, rowdata):
+        print(','.join(rowdata))
+
+
+class HTMLTableFormatter(TableFormatter):
+    """
+    Output portfolio data in HTML format.
+    """
+
+    def headings(self, headers):
+        print(f"<tr><th>{'</th><th>'.join(headers)}</th></tr>")
+
+    def row(self, rowdata):
+        print(f"<tr><td>{'</td><td>'.join(rowdata)}</td></tr>")
+
+
+class FormatError(Exception):
+    pass
+
+
+def create_formatter(fmt) -> TableFormatter:
+    if fmt == 'txt':
+        return TextTableFormatter()
+    elif fmt == 'csv':
+        return CSVTableFormatter()
+    elif fmt == 'html':
+        return HTMLTableFormatter()
+    else:
+        raise FormatError(f'Unknown format {fmt}')
diff --git a/Work/test_stock.py b/Work/test_stock.py
new file mode 100644
index 000000000..c9a5d48e1
--- /dev/null
+++ b/Work/test_stock.py
@@ -0,0 +1,20 @@
+from unittest import TestCase
+
+from Work.stock import Stock
+
+
+class TestStock(TestCase):
+    def test_create(self):
+        s = Stock('GOOG', 100, 490.1)
+        self.assertEqual(s.name, 'GOOG')
+        self.assertEqual(s.shares, 100)
+        self.assertEqual(s.price, 490.1)
+
+    def test_cost(self):
+        s = Stock("a", 100, 10.0)
+        self.assertEqual(s.cost, 1000)
+
+    def test_sell(self):
+        s = Stock("a", 100, 10.0)
+        s.sell(100)
+        self.assertEqual(s.shares, 0)
diff --git a/Work/typedproperty.py b/Work/typedproperty.py
new file mode 100644
index 000000000..150cbd61f
--- /dev/null
+++ b/Work/typedproperty.py
@@ -0,0 +1,19 @@
+def typedproperty(name, expected_type):
+    private_name = '_' + name
+
+    @property
+    def prop(self):
+        return getattr(self, private_name)
+
+    @prop.setter
+    def prop(self, value):
+        if not isinstance(value, expected_type):
+            raise TypeError(f'Expected {expected_type}')
+        setattr(self, private_name, value)
+
+    return prop
+
+
+StringProp = lambda name: typedproperty(name, str)
+IntProp = lambda name: typedproperty(name, int)
+FloatProp = lambda name: typedproperty(name, float)