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Utility functions for strings validation and manipulation.

Project description

Build Status codecov Documentation Status Python 3.5 Python 3.6 Python 3.7 Python 3.8

Python String Utils

Latest version: 1.0.0 (March 2020)

A handy library to validate, manipulate and generate strings, which is:

  • Simple and "pythonic"
  • Fully documented and with examples! (html version on
  • 100% code coverage! (see it with your own eyes on
  • Tested (automatically on each push thanks to Travis CI) against all officially supported Python versions
  • Fast (mostly based on compiled regex)
  • Free from external dependencies
  • PEP8 compliant

What's inside...

Library structure

The library basically consists in the python package string_utils, containing the following modules:

  • (contains string check api)
  • (contains string transformation api)
  • (contains string generation api)
  • (contains library-specific errors)
  • (contains compiled regex FOR INTERNAL USAGE ONLY)

Plus a secondary package tests which includes several submodules.
Specifically one for each test suite and named according to the api to test (eg. tests for is_ip() will be in and so on).

All the public API are importable directly from the main package string_utils, so this:

from string_utils.validation import is_ip

can be simplified as:

from string_utils import is_ip

Api overview

Bear in mind: this is just an overview, for the full API documentation see:

String validation functions:

is_string: checks if the given object is a string

is_string('hello') # returns true
is_string(b'hello') # returns false

is_full_string: checks if the given object is non empty string

is_full_string(None) # returns false
is_full_string('') # returns false
is_full_string(' ') # returns false
is_full_string('foo') # returns true

is_number: checks if the given string represents a valid number

is_number('42') # returns true
is_number('-25.99') # returns true
is_number('1e3') # returns true
is_number(' 1 2 3 ') # returns false

is_integer: checks if the given string represents a valid integer

is_integer('42') # returns true
is_integer('42.0') # returns false

is_decimal: checks if the given string represents a valid decimal number

is_decimal('42.0') # returns true
is_decimal('42') # returns false

is_url: checks if the given string is an url

is_url('') # returns false
is_url('') # returns true
is_url('') # returns true

is_email: Checks if the given string is an email

is_email('') # returns true
is_eamil('') # retruns false

is_credit_card: Checks if the given string is a credit card


# returns true if `value` represents a valid card number for one of these:

is_camel_case: Checks if the given string is formatted as camel case

is_camel_case('MyCamelCase') # returns true
is_camel_case('hello') # returns false

is_snake_case: Checks if the given string is formatted as snake case

is_snake_case('snake_bites') # returns true
is_snake_case('nope') # returns false

is_json: Checks if the given string is a valid json

is_json('{"first_name": "Peter", "last_name": "Parker"}') # returns true
is_json('[1, 2, 3]') # returns true
is_json('{nope}') # returns false

is_uuid: Checks if the given string is a valid UUID

is_uuid('ce2cd4ee-83de-46f6-a054-5ee4ddae1582') # returns true

is_ip_v4: Checks if the given string is a valid ip v4 address

is_ip_v4('') # returns true
is_ip_v4('') # returns false (999 is out of range)

is_ip_v6: Checks if the given string is a valid ip v6 address

is_ip_v6('2001:db8:85a3:0000:0000:8a2e:370:7334') # returns true
is_ip_v6('123:db8:85a3:0000:0000:8a2e:370,1') # returns false

is_ip: Checks if the given string is a valid ip (any version)

is_ip('') # returns true
is_ip('2001:db8:85a3:0000:0000:8a2e:370:7334') # returns true
is_ip('') # returns false
is_ip('123:db8:85a3:0000:0000:8a2e:370,1') # returns false

is_isnb_13: Checks if the given string is a valid ISBN 13

is_isbn_13('9780312498580') # returns true
is_isbn_13('978-0312498580') # returns true
is_isbn_13('978-0312498580', normalize=False) # returns false

is_isbn_10: Checks if the given string is a valid ISBN 10

is_isbn_10('1506715214') # returns true
is_isbn_10('150-6715214') # returns true
is_isbn_10('150-6715214', normalize=False) # returns false

is_isbn: Checks if the given string is a valid ISBN (any version)

is_isbn('9780312498580') # returns true
is_isbn('1506715214') # returns true

is_slug: Checks if the string is a slug (as created by slugify())

is_slug('my-blog-post-title') # returns true
is_slug('My blog post title') # returns false

contains_html: Checks if the strings contains one ore more HTML/XML tag

contains_html('my string is <strong>bold</strong>') # returns true
contains_html('my string is not bold') # returns false

words_count: Returns the number of words contained in the string

words_count('hello world') # returns 2
words_count('one,two,three') # returns 3 (no need for spaces, punctuation is recognized!)

is_palindrome: Checks if the string is a palindrome

is_palindrome('LOL') # returns true
is_palindrome('ROTFL') # returns false

is_pangram: Checks if the string is a pangram

is_pangram('The quick brown fox jumps over the lazy dog') # returns true
is_pangram('hello world') # returns false

is_isogram: Checks if the string is an isogram

is_isogram('dermatoglyphics') # returns true
is_isogram('hello') # returns false

String manipulation:

camel_case_to_snake: Converts a camel case formatted string into a snake case one

camel_case_to_snake('ThisIsACamelStringTest') # returns 'this_is_a_camel_case_string_test'

snake_case_to_camel: Converts a snake case formatted string into a camel case one

snake_case_to_camel('the_snake_is_green') # returns 'TheSnakeIsGreen'

reverse: Returns the string in a reversed order

reverse('hello') # returns 'olleh'

shuffle: Returns the string with its original chars but at randomized positions

shuffle('hello world') # possible output: 'l wodheorll'

strip_html: Removes all the HTML/XML tags found in a string

strip_html('test: <a href="foo/bar">click here</a>') # returns 'test: '
strip_html('test: <a href="foo/bar">click here</a>', keep_tag_content=True) # returns 'test: click here'

prettify: Reformat a string by applying basic grammar and formatting rules

prettify(' unprettified string ,, like this one,will be"prettified" .it\' s awesome! ')
# the ouput will be: 'Unprettified string, like this one, will be "prettified". It\'s awesome!'

asciify: Converts all non-ascii chars contained in a string into the closest possible ascii representation

# returns 'eeuuooaaeynAAACIINOE' (string is deliberately dumb in order to show char conversion)

slugify: Convert a string into a formatted "slug"

slugify('Top 10 Reasons To Love Dogs!!!') # returns: 'top-10-reasons-to-love-dogs'

booleanize: Convert a string into a boolean based on its content

booleanize('true') # returns true
booleanize('YES') # returns true
booleanize('y') # returns true
booleanize('1') # returns true
booelanize('something else') # returns false

strip_margin: Removes left indentation from multi-line strings (inspired by Scala)

        line 1
        line 2
        line 3

line 1
line 2
line 3

compress/decompress: Compress strings into shorted ones that can be restored back to the original one later on

compressed = compress(my_long_string) # shorter string (URL safe base64 encoded)

decompressed = decompress(compressed) # string restored

assert(my_long_string == decompressed) # yep

roman_encode: Encode integers/string into roman numbers

roman_encode(37) # returns 'XXXVII'

roman_decode: Decode roman number into an integer

roman_decode('XXXVII') # returns 37

roman_range: Generator which returns roman numbers on each iteration

for n in roman_range(10): print(n) # prints: I, II, III, IV, V, VI, VII, VIII, IX, X
for n in roman_range(start=7, stop=1, step=-1): print(n) # prints: VII, VI, V, IV, III, II, I

String generations:

uuid: Returns the string representation of a newly created UUID object

uuid() # possible output: 'ce2cd4ee-83de-46f6-a054-5ee4ddae1582'
uuid(as_hex=True) # possible output: 'ce2cd4ee83de46f6a0545ee4ddae1582'

random_string: Creates a string of the specified size with random chars

random_string(9) # possible output: 'K1URtlTu5'

secure_random_hex: Creates an hexadecimal string using a secure strong random generator

# possible ouput: 'd1eedff4033a2e9867c37ded' 
# (len is 24, because 12 represents the number of random bytes generated, which are then converted to hexadecimal value)


pip install python-string-utils

Checking installed version

import string_utils
'1.0.0' # (if '1.0.0' is the installed version)


Full API documentation available on

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