Feature/add initial commit

.github/workflows/python-test.yml

@@ -0,0 +1,28 @@
+name: Python application test with GitHub Actions
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        python-version: [3.11]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install -r dev-requirements.txt
+    - name: Test with pytest
+      run: |
+        pytest

Pipfile

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+# -----------------------------------------------------------------------------
+# The default Musicfox Pipfile.
+# 
+# This should be customized per application requirements; uncomment or add
+# those packages required. This should be used for datascience, web, and
+# most other Python-based projects, replacing raw venv or anaconda usage.
+# -----------------------------------------------------------------------------
+
+[[source]]
+url = "https://pypi.org/simple"
+verify_ssl = true
+name = "pypi"
+
+[dev-packages]
+ipython = "*"
+black = "*"
+pytest = "*"
+pytest-cov = "*"
+pynvim = "*"
+
+[packages]
+typer = {extras = ["all"], version = "*"}
+
+[requires]
+python_version = "3.11"

README.md

@@ -1,2 +1,36 @@
 # pi
-Using the Gauss-Legendre Algorithm to calculate Pi
+
+Using the Gauss-Legendre Algorithm to calculate Pi.
+
+## Usage
+
+```
+ Usage: pi.py [OPTIONS] COMMAND [ARGS]...
+
+╭─ Options ─────────────────────────────────────────────────────────────────────────╮
+│ --install-completion          Install completion for the current shell.           │
+│ --show-completion             Show completion for the current shell, to copy it   │
+│                               or customize the installation.                      │
+│ --help                        Show this message and exit.                         │
+╰───────────────────────────────────────────────────────────────────────────────────╯
+╭─ Commands ────────────────────────────────────────────────────────────────────────╮
+│ calculate-pi                 Returns the correct value of Pi up to the given      │
+│                              digits.                                              │
+│ calculate-pi-gauss-legendre  This implements the Gauss-Legendre algorithm to      │
+│                              calculate the value of Pi. Because it is memory      │
+│                              intensive, practitioners typically do not implement  │
+│                              this algorithm for actually calculating Pi.          │
+│ truncate-decimal             Truncates a Decimal value to a specified number of   │
+│                              decimal places.                                      │
+╰───────────────────────────────────────────────────────────────────────────────────╯
+```
+
+To calcualte Pi to 39 digits:
+
+```bash
+python pi.py calculate-pi 39
+```
+
+## Happy Pi Day 2024
+
+[tincre.com](https://tincre.com) made this to represent Pi day 2024 (March 14th, 2024). This library is entirely inconsequential but we're happy to accept contributions.

lock-dependencies.sh

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+#!/bin/bash
+echo "Locking dependencies using Python $(python --version)."
+
+echo "Generating requirements.txt..."
+pipenv requirements --hash > requirements.txt
+echo "Now generating dev-requirements.txt..."
+pipenv requirements --dev --hash > dev-requirements.txt
+echo "All dependencies generated with hashes. You should probably commit the changes."
+echo "You may do so via the following command:"
+echo "ga && gc ':heavy_plus_sign: <dependencyName> added'"

pi.py

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+from decimal import Decimal, getcontext
+import typer
+
+app = typer.Typer(name="π")
+
+
+@app.command()
+def calculate_pi_gauss_legendre(digits: int):
+    """
+    This implements the Gauss-Legendre algorithm to calculate the
+    value of Pi. Because it is memory intensive, practitioners typically
+    do not implement this algorithm for actually calculating Pi.
+
+    https://en.wikipedia.org/wiki/Gauss%E2%80%93Legendre_algorithm
+    """
+    getcontext().prec = digits + 2
+
+    a = Decimal(1)  # a_0
+    b = Decimal(1) / Decimal(2).sqrt()  # b_0
+    t = Decimal(1) / Decimal(4)  # t_0
+    p = Decimal(1)  # p_0
+
+    for _ in range(digits):
+        a_next = (a + b) / 2
+        b = (a * b).sqrt()
+        t -= p * (a - a_next) ** 2
+        a = a_next
+        p *= 2
+
+    return (a + b) ** 2 / (4 * t)
+
+
+@app.command()
+def truncate_decimal(value, places: int):
+    """Truncates a Decimal value to a specified number of decimal places."""
+    value_str = f"{value}"
+    dot_position = value_str.find(".")
+    return Decimal(
+        value_str[: dot_position + places + 1]
+        if dot_position != -1
+        else value_str
+    )
+
+
+@app.command()
+def calculate_pi(digits: int):
+    """Returns the correct value of Pi up to the given digits."""
+    return truncate_decimal(calculate_pi_gauss_legendre(digits), digits)
+
+
+if __name__ == "__main__":
+    app()

requirements.txt

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+-i https://pypi.org/simple
+click==8.1.7 ; python_version >= '3.7' --hash=sha256:ae74fb96c20a0277a1d615f1e4d73c8414f5a98db8b799a7931d1582f3390c28 --hash=sha256:ca9853ad459e787e2192211578cc907e7594e294c7ccc834310722b41b9ca6de
+colorama==0.4.6 --hash=sha256:08695f5cb7ed6e0531a20572697297273c47b8cae5a63ffc6d6ed5c201be6e44 --hash=sha256:4f1d9991f5acc0ca119f9d443620b77f9d6b33703e51011c16baf57afb285fc6
+markdown-it-py==3.0.0 ; python_version >= '3.8' --hash=sha256:355216845c60bd96232cd8d8c40e8f9765cc86f46880e43a8fd22dc1a1a8cab1 --hash=sha256:e3f60a94fa066dc52ec76661e37c851cb232d92f9886b15cb560aaada2df8feb
+mdurl==0.1.2 ; python_version >= '3.7' --hash=sha256:84008a41e51615a49fc9966191ff91509e3c40b939176e643fd50a5c2196b8f8 --hash=sha256:bb413d29f5eea38f31dd4754dd7377d4465116fb207585f97bf925588687c1ba
+pygments==2.17.2 ; python_version >= '3.7' --hash=sha256:b27c2826c47d0f3219f29554824c30c5e8945175d888647acd804ddd04af846c --hash=sha256:da46cec9fd2de5be3a8a784f434e4c4ab670b4ff54d605c4c2717e9d49c4c367
+rich==13.7.1 --hash=sha256:4edbae314f59eb482f54e9e30bf00d33350aaa94f4bfcd4e9e3110e64d0d7222 --hash=sha256:9be308cb1fe2f1f57d67ce99e95af38a1e2bc71ad9813b0e247cf7ffbcc3a432
+shellingham==1.5.4 --hash=sha256:7ecfff8f2fd72616f7481040475a65b2bf8af90a56c89140852d1120324e8686 --hash=sha256:8dbca0739d487e5bd35ab3ca4b36e11c4078f3a234bfce294b0a0291363404de
+typer[all]==0.9.0 --hash=sha256:50922fd79aea2f4751a8e0408ff10d2662bd0c8bbfa84755a699f3bada2978b2 --hash=sha256:5d96d986a21493606a358cae4461bd8cdf83cbf33a5aa950ae629ca3b51467ee
+typing-extensions==4.10.0 ; python_version >= '3.8' --hash=sha256:69b1a937c3a517342112fb4c6df7e72fc39a38e7891a5730ed4985b5214b5475 --hash=sha256:b0abd7c89e8fb96f98db18d86106ff1d90ab692004eb746cf6eda2682f91b3cb

test_pi.py

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+from pi import calculate_pi_gauss_legendre, truncate_decimal, calculate_pi
+from decimal import Decimal, getcontext
+import math
+
+
+def test_calculate_pi_gauss_legendre():
+    digits = 3
+    pi_approximation = calculate_pi_gauss_legendre(digits)
+    getcontext().prec = digits + 1
+    assert isinstance(pi_approximation, Decimal)
+    assert pi_approximation == Decimal(
+        "3.1416"
+    )  # the last digit should be wrong
+
+
+def test_truncate_decimal():
+    digits = 3
+    truncated = truncate_decimal(Decimal("1.1111"), digits)
+    assert len(f"{truncated}") == digits + 2  # for the decimal point and "1"
+
+
+def test_calculate_pi():
+    digits = 3
+    pi_approximation = calculate_pi(digits)
+    assert (
+        len(f"{pi_approximation}") == digits + 2
+    )  # for the decimal point and "3"
+    assert pi_approximation == Decimal("3.141")
+    digits = 39
+    pi_approximation = calculate_pi(digits)
+    assert (
+        len(f"{pi_approximation}") == digits + 2
+    )  # for the decimal point and "3"
+    assert pi_approximation == Decimal(
+        "3.141592653589793238462643383279502884197"
+    )
+    digits = 100
+    pi_approximation = calculate_pi(digits)
+    assert (
+        len(f"{pi_approximation}") == digits + 2
+    )  # for the decimal point and "3"
+    assert pi_approximation == Decimal(
+        "3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679"
+    )
+
+    # check against standard library
+    digits = 15
+    pi_approximation = calculate_pi(digits)
+    assert f"{pi_approximation}" == f"{math.pi}"