Octal Constants

In Python 2, an octal literal could be defined as

>>> 0755  # only Python 2

To ensure cross-compatibility, use

0o755  # both Python 2 and Python 3

Found a mistake? Have a question or improvement idea? Let me know.

Incompatibilities moving from Python 2 to Python 3:

*000Incompatibilities moving from Python 2 to Python 3

*Integer Division

*Unpacking Iterables

*Strings Bytes versus Unicode

*Print statement vs. Print function

*Differences between range and xrange functions

*Raising and handling Exceptions

*Leaked variables in list comprehension

*True False and None

*User Input

*Comparison of different types

*.next method on iterators renamed

*filter map and zip return iterators instead of sequences

*Renamed modules

*long vs. int

*Removed operators and synonymous with and repr

*Reduce is no longer a built-in

*All classes are new-style classes in Python 3

*AbsoluteRelative Imports

*map

*The round function tie-breaking and return type

*cmp function removed in Python 3

*File IO

*Return value when writing to a file object

*Octal Constants

*encode / decode to hex no longer available

*exec statement is a function in Python 3

*Dictionary method changes

*Class Boolean Value

*hasattr function bug in Python 2

Table Of Contents

11Sorting Minimum and Maximium

12Operator module

13Variable Scope and Binding

14Basic Input and Output

15Files, Folders, I/O

16JSON Module

17String Methods

18Metaclasses

19Indexing and Slicing

20Generators

21Simple Mathematical Operators

22Reduce

27Classes

31Set

33Parallel computation

34Multithreading

35Writing C extensions

36Unit Testing

37Regular Expressions

38Bitwise Operators

39Incompatibilities moving from Python 2 to Python 3

40Virtual environments

41Copying data

42Tuple

43Context Managers with Statement

45Enum

50The __name__ special variable

51Check if path exists

56Creating Python packages

57Parsing Command Line Arguments

62Sockets

68pip PyPI Package Manager

73Distributing self-contained applications

74Property Objects

75Overloading

76Debugging

77Reading and Writing CSV

78Dynamic code execution with exec and eval

79PyInstaller - Distributing Python Code

80Iterables and Iterators

81Data Visualization

82The interpreter command line console

87Security and Cryptograhy

88Pickle data serialization

89urllib

90Binary Data

91Python and Excel

92Idioms

93Method Overriding

94Difference between a module and a package

95Data Serialization

96Python Concurrency

97RabbitMQ using AMQPStorm

102Creating temporary files with tempfile

103Working with ZIP files

104Stack

105Profiling

106User-Defined Methods

107Working around Global Interpreter Lock

108Deployment using conda

109Logging

110Processes and Threads

111os module

112Comments and documentation

113Database Access

114Python HTTP Server

115Alternatives to switch statement from other languages

116List destructuring

117Accessing Python source code and bytecode

118Mixins

119Attribute Access

120ArcPy

121Python Anti-Patterns

122Plugin and Extension Classes

123Websockets

124Immutable data types

125String representations of class

126Arrays

127Operator Precedence

128Polymorphism

129Alternative Python implementations

130List Comprehensions

131Web Server Gateway Intrerface WSGI

1322to3 tool

133Abstract Syntax Tree

134Abstract Base Classes

135Unicode

136ssh in Python

137Serial Communication with pyserial

138Neo4j

139Performance optimization

140Curses

141Templates

142pass statement

143Testing with py.test

144Date Formatting

145heapq

146tkinter

147CLI subcommands

148Defining functions with list arguments

149SQLite3 module

150Persistence with pickle

151Connecting to SQL Server

152Design Patterns

153Multidimensional arrays

154Audio

155pyglet

156queue module

157ijson

158webbrowser module

159base64 module

160Flask

161Groupby

162Sockets and Message Encryption / Decryption

163pygame

164Input Subset and Output External Data Files using Pandas

165hashlib

166Gzip

167ctypes

168Creating a Windows Service

169Mutable vs. Immutable

170configparser

171Common Exceptions

172Optical Character Recognition OCR

177Functional Programming

178Python Virtual Environment - virtualenv

179sys module

180virtual environment with virtualenvwrapper

181virtualenvwrapper on Windows

182Python Requests Post

183Plotting with Matplotlib

184Python Lex-Yacc

185pyaudio

186shelve

187pip and PyPI Package Manager

188Writing to CSV from String or List

189Raise Custom Errors Exceptions

190Using loops within functions

191Contributors