__pycache__: Initial commit (materials)

Author: bzaczynski

python-pycache/Calculator.java

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+public class Calculator {
+    public static void main(String[] args) {
+        add(3, 4);
+    }
+
+    private static int add(int a, int b) {
+        return a + b;
+    }
+}

python-pycache/README.md

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+# What Is the __pycache__ Folder in Python?
+
+Source code, shell scripts, and example projects for the [What Is the `__pycache__` Folder in Python?](https://realpython.com/python-pycache/) tutorial on Real Python.
+
+## Setup
+
+You don't need to create a virtual environments because you won't be installing anything.
+
+## Cleanup Scripts
+
+To recursively remove the `__pycache__` folders on macOS and Linux:
+
+```shell
+$ ./pyclean.sh
+```
+
+To do the same on Windows in PowerShell:
+
+```shell
+PS> .\pyclean.ps1
+```
+
+## X-Ray of `.pyc` Files
+
+Compile sample bytecode into timestamp-based `.pyc` files:
+
+```shell
+$ ./pyclean.sh
+$ python -m compileall --invalidation-mode timestamp example-2/
+$ python xray.py example-2/__pycache__/arithmetic*.pyc
+{'magic_number': b'\xcb\r\r\n',
+ 'magic_int': 3531,
+ 'python_version': '3.12',
+ 'bit_field': 0,
+ 'pyc_type': <PycInvalidationMode.TIMESTAMP: 1>,
+ 'timestamp': datetime.datetime(2024, 3, 28, 17, 8, 22, tzinfo=datetime.timezone.utc),
+ 'file_size': 32}
+```
+
+Compile sample bytecode into unchecked hash-based `.pyc` files:
+
+```shell
+$ ./pyclean.sh
+$ python -m compileall --invalidation-mode unchecked-hash example-2/
+$ python xray.py example-2/__pycache__/arithmetic*.pyc
+{'magic_number': b'\xcb\r\r\n',
+ 'magic_int': 3531,
+ 'python_version': '3.12',
+ 'bit_field': 1,
+ 'pyc_type': <PycInvalidationMode.UNCHECKED_HASH: 3>,
+ 'hash_value': b'\xf3\xdd\x87j\x8d>\x0e)'}
+```
+
+Compile sample bytecode into checked hash-based `.pyc` files:
+
+```shell
+$ ./pyclean.sh
+$ python -m compileall --invalidation-mode checked-hash example-2/
+$ python xray.py example-2/__pycache__/arithmetic*.pyc
+{'magic_number': b'\xcb\r\r\n',
+ 'magic_int': 3531,
+ 'python_version': '3.12',
+ 'bit_field': 3,
+ 'pyc_type': <PycInvalidationMode.CHECKED_HASH: 2>,
+ 'hash_value': b'\xf3\xdd\x87j\x8d>\x0e)'}
+```
+
+## Java Bytecode Compiler
+
+Compile the source code upfront and run the resulting class file:
+
+```shell
+$ javac Calculator.java
+$ time java Calculator
+```
+
+Let the `java` command handle the compilation:
+
+```shell
+$ time java Calculator.java
+```

python-pycache/example-1/project/calculator.py

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+import mathematics.geometry  # noqa

python-pycache/example-1/project/mathematics/__init__.py

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+def add(a, b):
+    return a + b

python-pycache/example-1/project/mathematics/arithmetic/__init__.py

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+def sub(a, b):
+    return a - b

python-pycache/example-1/project/mathematics/arithmetic/add.py

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+def add(a, b):
+    return a + b