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--- notes:python_cheat_sheet [2026/06/11 15:18]
114.119.132.52 old revision restored (2009/04/03 16:14)
+++ notes:python_cheat_sheet [2026/06/16 02:03] (current)
47.79.10.239 old revision restored (2026/05/27 22:27)
@@ Line 77: / Line 77: @@
   * Loops may have else clauses for code executed after normal termination (not a break).
+===== Assorted Collection Stuff =====
+  * Dictionaries are unordered sets of key value pairs e.g. { a:1, b:2} or dict([(a,1),(b,2)]) or dict(a=1,b=2)
+  * Dictionary keys/values/items can be enumerated over.
+  * sorted and reversed take in liats and return new lists.
+  * enumerate takes in a list and returns a list of pairs where the first item in the pair is an integer starting with 0.
+  * zip takes two or more lists with the same number of elements and creates a single list of lists with corresponding members grouped together.
+===== Modules & Packages =====
+  * A //module// is a file of python definitions.
+  * Definitions in a module can be accessed by importing the module. <code python>import fib
+from fib import fib1, fib2
+</code>
+  * __name__ is set to the name of the module or to __main__ if called from the command line.
+  * The search list for modules is the variable sys.path initialized from the directory containing the input script (or the current directory), PYTHONPATH and the installation-dependent default.
+  * When a module is imported, a byte-code version is stored to module.pyc which speeds up successive loads.
+  * There are many standard modules including sys which is common to all platforms.
+  * dir(module) lists all names in a module sorted alphabetically. dir(builtins) shows all the built-in functions and variables.
+  * Packages can be used to group modules. Packages should be in a named directory with an __init__.py file optionally containing initialization code. E.g. import sound.effects.echo .
+  * . is the current package, .. is the parent package etc.

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