python version of exercise

python/.gitignore

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+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+env/
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*,cover
+.hypothesis/
+.pytest_cache
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+
+# Flask instance folder
+instance/
+
+# Sphinx documentation
+docs/_build/
+
+# MkDocs documentation
+/site/
+
+# PyBuilder
+target/
+
+# IPython Notebook
+.ipynb_checkpoints
+
+# pyenv
+.python-version
+venv
+
+.idea

python/requirements.txt

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+pytest
+approvaltests
+pytest-approvaltests

python/statement.py

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+import math
+
+
+def statement(invoice, plays):
+    total_amount = 0
+    volume_credits = 0
+    result = f'Statement for {invoice["customer"]}\n'
+
+    def format_as_dollars(amount):
+        return f"${amount:0,.2f}"
+
+    for perf in invoice['performances']:
+        play = plays[perf['playID']]
+        if play['type'] == "tragedy":
+            this_amount = 40000
+            if perf['audience'] > 30:
+                this_amount += 1000 * (perf['audience'] - 30)
+        elif play['type'] == "comedy":
+            this_amount = 30000
+            if perf['audience'] > 20:
+                this_amount += 10000 + 500 * (perf['audience'] - 20)
+
+            this_amount += 300 * perf['audience']
+
+        else:
+            raise ValueError(f'unknown type: {play["type"]}')
+
+        # add volume credits
+        volume_credits += max(perf['audience'] - 30, 0)
+        # add extra credit for every ten comedy attendees
+        if "comedy" == play["type"]:
+            volume_credits += math.floor(perf['audience'] / 5)
+        # print line for this order
+        result += f' {play["name"]}: {format_as_dollars(this_amount/100)} ({perf["audience"]} seats)\n'
+        total_amount += this_amount
+
+    result += f'Amount owed is {format_as_dollars(total_amount/100)}\n'
+    result += f'You earned {volume_credits} credits\n'
+    return result
+
+

python/tests/invoice.json

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+{
+  "customer": "BigCo",
+  "performances": [
+    {
+      "playID": "hamlet",
+      "audience": 55
+    },
+    {
+      "playID": "as-like",
+      "audience": 35
+    },
+    {
+      "playID": "othello",
+      "audience": 40
+    }
+  ]
+}

python/tests/invoice_new_plays.json

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+{
+  "customer": "BigCoII",
+  "performances": [
+    {
+      "playID": "henry-v",
+      "audience": 53
+    },
+    {
+      "playID": "as-like",
+      "audience": 55
+    }
+  ]
+}

python/tests/new_plays.json

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+{
+  "henry-v": {"name": "Henry V", "type": "history"},
+  "as-like": {"name": "As You Like It", "type": "pastoral"}
+}

python/tests/plays.json

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+{
+  "hamlet": {"name": "Hamlet", "type": "tragedy"},
+  "as-like": {"name": "As You Like It", "type": "comedy"},
+  "othello": {"name": "Othello", "type": "tragedy"}
+}

python/tests/test_statement.py

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+import json
+
+import pytest
+from approvaltests import verify
+from approvaltests.utils import get_adjacent_file
+
+from statement import statement
+
+
+def test_example_statement():
+    with open(get_adjacent_file("invoice.json")) as f:
+        invoice = json.loads(f.read())
+    with open(get_adjacent_file("plays.json")) as f:
+        plays = json.loads(f.read())
+    verify(statement(invoice, plays))
+
+
+def test_statement_with_new_play_types():
+    with open(get_adjacent_file("invoice_new_plays.json")) as f:
+        invoice = json.loads(f.read())
+    with open(get_adjacent_file("new_plays.json")) as f:
+        plays = json.loads(f.read())
+    with pytest.raises(ValueError) as exception_info:
+        statement(invoice, plays)
+    assert "unknown type" in str(exception_info.value)

python/tests/test_statement.test_example_statement.approved.txt

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+Statement for BigCo
+ Hamlet: $650.00 (55 seats)
+ As You Like It: $580.00 (35 seats)
+ Othello: $500.00 (40 seats)
+Amount owed is $1,730.00
+You earned 47 credits