Python Regular Expressions (regex): Forming a Regular Expression in Python

As the saying goes, "I never metacharacter I didn't like." Once you learn how to use metacharacters, you will wonder how you ever got on without them. This is particularly true in Python. Python has a robust regular expression engine and employs a wide array of metacharacters. The following is a list of the symbols and their uses:

• .: any character except a newline.
• ^: the boundary at the beginning of a character string (the green line)
• $: the boundary at the end of a character string (the other green line)
• *: zero or more instances of a pattern
• +: one or more instances of a pattern
• ?: one or more instances of a pattern
• \: the indicator of an escape sequence
• {}: used to specify parameters for the matching of the regular expression
• []: indicates a set of characters for a single position in the regex
• (): used to group regular expressions
• |: used as an 'or' between two possible matches.

• Half the Battle: How Python Understand Regular Expressions
• How Python Views a String: Every Dog has Its Null Value
• How Did the Python Eat the String? One Byte at a Time
• Python Strings Along Dogs and Cats
• "I never metacharacter I didn't like."
• Python's Compound Metacharacters
• Curly Braces in Python Regular Expressions
• Tightening Python's Grip: Ranges in Python Pattern Matching
• An Example of Pattern Matching in Python
• An Explanation of Forming RegEx in Python