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sre_constants Module

The sre_constants module defines constants used internally by the regex engine and the sre_compile/sre_parse modules.

Complexity Reference

Operation Time Space Notes
Access constant O(1) O(1) Static constants
Lookup opcode O(1) O(1) Hash table

Regex Engine Constants

Using Regex Constants

import sre_constants

# Access opcodes - O(1)
print(sre_constants.LITERAL)      # Regular character
print(sre_constants.BRANCH)       # | operator
print(sre_constants.RANGE)        # Character range [a-z]

# View all opcodes
for name in dir(sre_constants):
    if name.isupper():
        print(f"{name}: {getattr(sre_constants, name)}")