str.translate()

str.translate(table)

The .translate() method returns a copy of the string where each character has been mapped through a translation table. It’s commonly used for character-level replacements, deletions, and Unicode normalization. The method works closely with str.maketrans(), which creates the translation table.

Syntax

str.translate(table)

Parameters

Parameter	Type	Description
table	dict or None	A dictionary mapping Unicode ordinals (integers) or characters to Unicode ordinals, strings, or None. If None, delete the mappings.

Returns: A new string with characters mapped according to the table.

Creating Translation Tables

Using str.maketrans()

The str.maketrans() function creates a translation table for use with .translate():

>>> table = str.maketrans({'a': 'x', 'e': 'y'})
>>> "hello world".translate(table)
'hyllo world'

With two arguments (character-to-character mapping)

>>> table = str.maketrans('aeiou', '12345')
>>> "hello world".translate(table)
'h2ll4 w4rld'

With optional third argument (characters to delete)

>>> table = str.maketrans('aeiou', '12345', 'l')
>>> "hello world".translate(table)
'he44 w4rd'

Examples

Basic character replacement

>>> table = {'a': 'z', 'b': 'y'}
>>> "abc".translate(table)
'zyc'

Deleting characters

>>> "hello world".translate({ord(c): None for c in 'aeiou'})
'hll wrld'

Or using the third argument to maketrans():

>>> table = str.maketrans('', '', 'aeiou')
>>> "hello world".translate(table)
'hll wrld'

Unicode character translation

>>> table = {ord('é'): ord('e'), ord('ü'): ord('u')}
>>> "café résumé".translate(table)
'cafe resume'

Practical: cleaning user input

# Remove all non-ASCII characters
>>> table = str.maketrans('', '', ''.join(chr(i) for i in range(128, 256)))
>>> "hello café world 😀".translate(table)
'hello cfe world '

Converting to ASCII-compatible text

# Replace non-ASCII with closest ASCII equivalents
trans_table = str.maketrans({
    'à': 'a', 'á': 'a', 'â': 'a',
    'é': 'e', 'è': 'e', 'ê': 'e',
    'ñ': 'n', 'ü': 'u', 'ö': 'o'
})
>>> "café résumé naïve".translate(trans_table)
'cafe resume naive'

Common Patterns

Removing punctuation

>>> import string
>>> table = str.maketrans('', '', string.punctuation)
>>> "Hello, world!".translate(table)
'Helloworld'

Normalizing whitespace

# Replace multiple spaces with single space
>>> "hello    world".translate(str.maketrans('', '', '\t\n\r\x0b\x0c'))
'hello world'

Character case conversion with delete

>>> table = str.maketrans('', '', string.ascii_lowercase)
>>> "Hello123".translate(table)
'H123'

Differences from replace()

• .translate() works at the character level using a mapping table
• .replace() works with string substitution patterns
• .translate() is faster for bulk character operations
• .translate() can delete characters (by mapping to None)

# Using replace() - word by word
>>> "hello hello".replace("l", "x")
'hexxo hexxo'

# Using translate() - character by character
>>> "hello hello".translate(str.maketrans('l', 'x'))
'hexxo hexxo'

Errors

• If table is not a dictionary or None, TypeError is raised

>>> "hello".translate("invalid")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: translation table must be dict, None, or a callable

See Also

• str.replace()
• str.maketrans()
• str.encode()