Introduction and Basic Functions
2 min read ·
Regular Expressions are used to search, match, and manipulate text based on patterns. Python provides a built in module called
re to work with regular expressions.re Module
To use regular expressions in Python, you need to import the
re module.match()
The
match() function checks for a match only at the beginning of the string.If match is found:
Note
match() only works if the pattern is at the start of the string.
search()
The
search() function scans the entire string and returns first match.findall()
The
findall() function returns all matches in a list.finditer()
The
finditer() function returns an iterator of match objects.Pro Tip
Use findall() when you want list of results and finditer() when you need position and detailed info.
Understanding Difference
- match() → checks from beginning
- search() → finds first occurrence anywhere
- findall() → returns all matches as list
- finditer() → returns match objects with details
Caution
Regular expressions are case sensitive by default.
Exercise
- Use match() to check if string starts with a word
- Use search() to find word inside string
- Use findall() to get all occurrences
- Use finditer() to print match positions