translate() : each char is mapped to matching chars in translation table in Python

translate() , maketrans() : Search replace and delete of set of chars.

str_update=str_input.maketrans(str_search,str_replace,str_delete)

str_search : Required, Chars to be searched
str_replace: Required, Chars to be replaced ( mapped to searched chars )
str_delete : Optional, Chars to be replaced with None ( deleted in final string )

Length of str_search should be equal to length of str_replace
the method maketrans() returns a dictionary ( str_update ) with chars mapped for search and replace and this can be used for translate().

str_search='abc'  # search chars 
str_replace='xyz' # replace chars 
str_delete='pqr'  # delete chars 

str_input='abcdefghpqr' #input string 

str_update=str_input.maketrans(str_search,str_replace,str_delete)

print(str_update) # dictionary output with chars mapped. 
print("input string : ",str_input)
print("Output string: ",str_input.translate(str_update))

Output

{97: 120, 98: 121, 99: 122, 112: None, 113: None, 114: None}
input string :  abcdefghpqr
Output string:  xyzdefgh

The `translate()` function works with `maketrans()` to replace or remove characters in a string based on a translation table. `maketrans()` helps define a mapping for character replacements or deletions, which `translate()` applies.

Syntax

str.translate(translation_table)

Example 1: Basic Mapping with translate()

Mapping characters with `maketrans()` and applying with `translate()`.

str_input = "abcdef"
table = str.maketrans("abc", "xyz")
print(str_input.translate(table))

Output:

xyzdef

Example 2: Mapping and Removing Specific Characters

Removing specific characters from a string by passing `None` in `maketrans()`.

str_input = "hello world!"
table = str.maketrans("", "", "aeiou")
print(str_input.translate(table))

Output:

hll wrld!

Example 3: Multiple Character Mappings with translate()

Using `translate()` to swap multiple characters in a string.

str_input = "apple pie"
table = str.maketrans("ap", "xy", "e")
print(str_input.translate(table))

Output:

xyyl yi

Applications of translate()

Data Cleaning: Useful for removing unwanted characters in text processing.
Encryption and Encoding: Basic character substitution in simple ciphers.
Text Normalization: Helpful for replacing unwanted characters in structured data.

All String methods

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Subhendu Mohapatra

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translate(): Mapping and Removing Characters

Syntax

Example 1: Basic Mapping with translate()

Example 2: Mapping and Removing Specific Characters

Example 3: Multiple Character Mappings with translate()

Applications of translate()

Subhendu Mohapatra