Further Reading

Note that some of these resources are not specific to Python. So you'll have to adapt them to Python's syntax.

• docs.python: Regular Expression HOWTO
• Python 3 Module of the Week: re — covers till Python version 3.7.9
• stackoverflow: python regex
• PythonVerbalExpressions — construct regular expressions with natural language terms
• CommonRegex — collection of common regular expressions
• Awesome Regex — curated collection of libraries, tools, frameworks and software
• Generate strings that match a given regular expression
• stackoverflow: regex FAQ
  • stackoverflow: regex tag is a good source of exercise questions
• rexegg — tutorials, tricks and more
• regular-expressions — tutorials and tools
• regexcrossword — tutorials and puzzles, only supports JavaScript flavor
• regex101 — visual aid and online testing tool for regular expressions, select flavor as Python before use
• debuggex — railroad diagrams for regular expressions, select flavor as Python before use
• swtch — stuff about regular expression implementation engines

Here are resources for specific topics:

• rexegg: best regex trick
• rexegg: Backtracking Control Verbs
• regular-expressions: matching numeric ranges
• regular-expressions: Continuing at The End of The Previous Match
• regular-expressions: Zero-Length Matches
• stackoverflow: Greedy vs Reluctant vs Possessive Quantifiers