string
The string library provides string constants for character classification, such as ASCII letters, digits, and punctuation. It is commonly used for validating input or building character sets, matching Python’s string module.
Available Functions
This library has no functions, only constants.
Constants
| Constant | Description |
|---|---|
ascii_letters |
Concatenation of ascii_lowercase and ascii_uppercase ("abc...xyzABC...XYZ") |
ascii_lowercase |
Lowercase ASCII letters ("abcdefghijklmnopqrstuvwxyz") |
ascii_uppercase |
Uppercase ASCII letters ("ABCDEFGHIJKLMNOPQRSTUVWXYZ") |
digits |
Decimal digits ("0123456789") |
hexdigits |
Hexadecimal digits ("0123456789abcdefABCDEF") |
octdigits |
Octal digits ("01234567") |
punctuation |
ASCII punctuation characters (`` “!"#$%&’()*+,-./:;<=>?@[\]^_`{ |
whitespace |
Whitespace characters (" \t\n\r\v\f") |
printable |
Concatenation of digits, ascii_letters, punctuation, and whitespace |
string.ascii_letters
Concatenation of ascii_lowercase and ascii_uppercase.
Value: str ("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
import string
print(string.ascii_letters) # "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"string.ascii_lowercase
Lowercase ASCII letters.
Value: str ("abcdefghijklmnopqrstuvwxyz")
import string
print(string.ascii_lowercase) # "abcdefghijklmnopqrstuvwxyz"string.ascii_uppercase
Uppercase ASCII letters.
Value: str ("ABCDEFGHIJKLMNOPQRSTUVWXYZ")
import string
print(string.ascii_uppercase) # "ABCDEFGHIJKLMNOPQRSTUVWXYZ"string.digits
Decimal digits.
Value: str ("0123456789")
import string
print(string.digits) # "0123456789"string.hexdigits
Hexadecimal digits, including both lowercase and uppercase letter forms.
Value: str ("0123456789abcdefABCDEF")
import string
print(string.hexdigits) # "0123456789abcdefABCDEF"string.octdigits
Octal digits.
Value: str ("01234567")
import string
print(string.octdigits) # "01234567"string.punctuation
ASCII punctuation characters.
Value: str ("!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~")
import string
print(string.punctuation) # "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~"string.whitespace
Whitespace characters: space, tab, newline, carriage return, vertical tab, and form feed.
Value: str (" \t\n\r\v\f")
import string
print(repr(string.whitespace)) # ' \t\n\r\x0b\x0c'string.printable
Concatenation of digits, ascii_letters, punctuation, and whitespace.
Value: str
import string
print(string.printable)Examples
Character Validation
import string
def is_valid_identifier(s):
if len(s) == 0:
return False
# First char must be letter or underscore
if s[0] not in string.ascii_letters + "_":
return False
# Rest can include digits
valid = string.ascii_letters + string.digits + "_"
for c in s:
if c not in valid:
return False
return True
print(is_valid_identifier("my_var")) # True
print(is_valid_identifier("123abc")) # FalseGenerate Random String
import string
import random
def random_string(length):
chars = string.ascii_letters + string.digits
result = ""
for i in range(length):
result = result + random.choice(chars)
return result
print(random_string(10)) # e.g., "aB3xY7mK2p"Check for Hex String
import string
def is_hex(s):
for c in s:
if c not in string.hexdigits:
return False
return True
print(is_hex("deadbeef")) # True
print(is_hex("xyz123")) # FalsePython Compatibility
This module provides the same constants as Python’s string module.