str.maketrans()

str.maketrans(x[, y[, z]])

The maketrans() method creates a translation table that can be used with the translate() method. It is useful when you need to replace or remove specific characters from a string.

Syntax

str.maketrans(x[, y[, z]])

Parameters

The method can be called in three different ways:

Single argument (dictionary)

• x: A dictionary that maps Unicode ordinals (integers) or characters to Unicode ordinals, strings, or None

Two arguments (two strings)

• x: A string of characters to be replaced
• y: A string of replacement characters (must be same length as x)

Three arguments (two strings + one string)

• x: A string of characters to be replaced
• y: A string of replacement characters (must be same length as x)
• z: A string of characters to be deleted

Returns: A dictionary representing the translation table.

Examples

Basic character replacement with two arguments

# Create a translation table
table = str.maketrans("aeiou", "AEIOU")

# Apply it to a string
text = "hello world"
print(text.translate(table))
# hEllO wOrld

The first string specifies characters to replace, and the second specifies their replacements. Positions are matched one-to-one.

Using a dictionary

# Map specific characters using a dictionary
table = str.maketrans({
    ord('a'): ord('x'),
    ord('e'): ord('y'),
    ord('i'): ord('z')
})

text = "aeiou"
print(text.translate(table))
# xyzou

This approach gives you precise control over which characters get translated to what.

Deleting characters with three arguments

# Delete vowels from the string
table = str.maketrans("aeiou", "aeiou", "aeiou")

text = "hello world"
print(text.translate(table))
# hll wrld

When three arguments are provided, the third string specifies characters to delete entirely.

Practical example: sanitizing input

# Remove non-alphanumeric characters except spaces
special_chars = "!@#$%^&*()_+-=[]{}|;':\",./<>?"
table = str.maketrans("", "", special_chars)

text = "hello@world#2024!"
print(text.translate(table))
# helloworld2024

This is useful for cleaning user input or normalizing strings.

Converting case with maketrans

# Swap uppercase for lowercase and vice versa
import string
table = str.maketrans(string.ascii_uppercase, string.ascii_lowercase)

text = "HELLO World"
print(text.translate(table))
# hello world

Common Patterns

Password sanitization

# Remove special characters from a potential password
special_chars = "!@#$%^&*()_+-=[]{}|;':\",./<>?"
table = str.maketrans("", "", special_chars)

password = "p@ssw0rd!123"
safe = password.translate(table)
print(safe)
# password123

Normalizing text

# Replace various dash characters with regular hyphen
dashes = "–—−"  # en-dash, em-dash, minus sign
table = str.maketrans(dashes, "---")

text = "Hello – World — is − here"
print(text.translate(table))
# Hello - World - is - here

Return Value

maketrans() returns a dictionary that maps Unicode ordinals to either:

• Another ordinal (for replacement)
• A string (for replacement)
• None (for deletion)

This dictionary is then passed to the translate() method.

See Also

• str.replace()
• str.translate()
• str.encode()