Popular Python recipes tagged "string"

Bytes-to-human / human-to-bytes converter (Python)

2012-02-02T16:09:52-08:00

Python recipe 578019 by Giampaolo Rodolà (bytes, conversion, converter, human, humanize, string). Revision 15.

Here goes.

Use PrettyTable and xtopdf to create PDF tables with borders, alignment and padding (Python)

2015-01-24T21:21:27-08:00

Python recipe 579012 by Vasudev Ram (data, pdf, prettytable, string, tabular, xtopdf).

This recipe shows how to create tabular data in PDF format, supporting neat borders, and alignment and padding of columns, using the Python libraries called PrettyTable and xtopdf.

Random Password Generation (Python)

2014-08-10T15:50:40-07:00

Python recipe 578920 by Paul Wolf (generator, password, python, random, string, strong).

Generate a password (or other secure token) using a pattern language similar to regular expressions. We'll use the strgen module that enables a user to generate test data, unique ids, passwords, vouchers or other randomized data very quickly using a template language. The template language is superficially similar to regular expressions but instead of defining how to match or capture strings, it defines how to generate randomized strings.

String to Binary (Python)

2014-07-30T07:20:22-07:00

Python recipe 578291 by p@ntut$ (binary, string, to). Revision 2.

String to binary snippet, python3+

Decimal Number To Byte(s) And String To Byte(s) Converter. (Python)

2012-01-24T21:11:47-08:00

Python recipe 578025 by Barry Walker (bytes, converter, decimal, linux, string, windows).

A function to convert decimal integer numbers, (from 0 to 255), into byte(s) format. Another function calling the above function to convert ASCII strings into byte(s) format.

Python 3.1.3 (r313:86834, Nov 28 2010, 10:01:07) [GCC 4.4.5] on linux2 Type "help", "copyright", "credits" or "license" for more information.

>>> exec(open('/home/G0LCU/Desktop/Code/d2b.py').read())
>>> a=78
>>> type(a)
<class 'int'>
>>> b=d2b(a)
>>> print(b)
b'N'
>>> type(b)
<class 'bytes'>
>>> text="\x00(C)2012, B.Walker, G0LCU.\xFF"
>>> len(text)
27
>>> type(text)
<class 'str'>
>>> newtext=t2b(text)
>>> len(newtext)
27
>>> print(newtext)
b'\x00(C)2012, B.Walker, G0LCU.\xff'
>>> type(newtext)
<class 'bytes'>

It requires NOTHING special at all to work and can be run like above or imported from the correct "Lib" drawer/folder/directorfy as:-

>>> import d2b

And when imported called as:-

>>> d2b.d2b(some_number, optional_some_other_mumber)<RETURN/ENTER>

>>> d2b.t2b(some_ASCII_string)<RETURN/ENTER>

Read the code for much more information...

Issued under the GPL2 licence.

Enjoy finding simple solutions to often very difficult problems.

Bazza, G0LCU.

lreplace() and rreplace(): Replace the beginning and ends of a strings (Python)

2010-06-04T02:18:48-07:00

Python recipe 577252 by Dan McDougall (regex, replace, string).

Python newbies will often make the following mistake (I certainly have =):

>>> test = """this is a test:
... tis the season for mistakes."""
>>> for line in test.split('\n'):
...     print line.lstrip('this')
... 
 is a test
 the season for mistakes.

The mistake is assuming that lstrip() (or rstrip()) strips a string (whole) when it actually strips all of the provided characters in the given string. Python actually comes with no function to strip a string from the left-hand or right-hand side of a string so I wrote this (very simple) recipe to solve that problem. Here's the usage:

>>> test = """this is a test:
... tis the season for mistakes."""
>>> for line in test.split('\n'):
...     print lreplace('this', '', line)
... 
 is a test
tis the season for mistakes.

I really wish Python had these functions built into the string object. I think it would be a useful addition to the standard library. It would also be nicer to type this:

line.lreplace('this', '')

Instead of this:

lreplace('this','',line)

get all possible combinations of characters given a string (Python)

2011-08-15T04:15:42-07:00

Python recipe 577842 by Yang (algorithms, permutation, string).

This will give a result that is more than a permutation, but all possible combinations. An example is when input is 'abc', the output would be: a,ab,abc,ac,acb,b,ba,bac,bc,bca,c,ca,cab,cb,cba

Search sequences for sub-sequence (Python)

2011-08-19T05:17:00-07:00

Python recipe 577850 by Steven D'Aprano (find, searching, sequence, string, sublist, substring).

The list and tuple index() method and in operator test for element containment, unlike similar tests for strings, which checks for sub-strings:

>>> "12" in "0123"
True
>>> [1, 2] in [0, 1, 2, 3]
False

These two functions, search and rsearch, act like str.find() except they operate on any arbitrary sequence such as lists:

>>> search([1, "a", "b", 2, 3], ["b", 2])
2

Split Strings w/ Multiple Separators (Python)

2011-03-20T20:33:13-07:00

Python recipe 577616 by Kenneth Reitz (split, string, string_parsing). Revision 5.

Splits strings with multiple separators instead of one (e.g. str.split()).

"Comma float" to float (Python)

2010-02-11T22:19:41-08:00

Python recipe 577054 by Matevz Lesko (comma, float, numbers, string). Revision 2.

Convert comma separated floating point number (12,3456) to float.

converting numbers to their alphabetical style (Python)

2011-03-17T06:57:06-07:00

Python recipe 577607 by amir naghavi (algorithm, recursion, string). Revision 4.

converts numbers to alphabetical numbers

Auto Named Decriptors (Python)

2010-10-19T22:55:16-07:00

Python recipe 577426 by Aloys Baillet (automatically, constants, descriptors, metaclass, name, string). Revision 3.

Using named Descriptors? Tired of duplicating the name of the instance in a string? A small metaclass can solve this.

Split a string on capitalized / uppercase char using Python (Python)

2009-12-11T23:16:36-08:00

Python recipe 576984 by activestate (string, string_parsing, text_processing). Revision 6.

By user http://code.activestate.com/recipes/users/2629617/ in comment on http://code.activestate.com/recipes/440698/ but modified slightly.

Splits any string on upper case characters.

Ex.

>>> print split_uppercase("thisIsIt and SoIsThis")
this Is It and  So Is This

note the two spaces after 'and'

string Formatter that renders None values as empty strings (Python)

2010-05-14T18:35:27-07:00

Python recipe 577227 by Antonio Cuni (formatting, none, string).

This string Formatter works exactly as the default string.Formatter one (i.e., as str.format), with the exception that None values are rendered as empty strings instead of "None". Moreover, any attempt to access attributes or items of None values is rendered as an empty string as well, instead of raising an exception.
E.g. fmt.format('{a}{a.foo}{a[0]}', a=None) == ''

This is useful e.g. when filling a template with values that are fetched from a DB, where usually None means empty.

Approximately Equal (Python)

2010-03-17T17:05:51-07:00

Python recipe 577124 by Steven D'Aprano (comparisons, distance, math, maths, numeric, string).

Generic "approximately equal" function for any object type, with customisable error tolerance.

When called with float arguments, approx_equal(x, y[, tol[, rel]) compares x and y numerically, and returns True if y is within either absolute error tol or relative error rel of x, otherwise return False. The function defaults to sensible default values for tol and rel.

For any other pair of objects, approx_equal() looks for a method __approx_equal__ and, if found, calls it with arbitrary optional arguments. This allows types to define their own concept of "close enough".

Scramble a string of words, preserving spaces (Python)

2010-06-25T20:44:04-07:00

Python recipe 577275 by Kai Mallea (scramble, string, words).

The following function will scramble a string, preserving spaces that separate the words, and return the result. I used this for a word game that scrambled words and phrases, which a player then attempted to descramble. For example, scrambling the following string: "teenage mutant ninja turtles" would return "etegnae tamtnu jnnai urtltes"

partitionall() - partition until the end (Python)

2010-03-01T15:27:07-08:00

Python recipe 577060 by Shashwat Anand (string). Revision 4.

Search for the separator sep in string s, and return the part before it, the separator itself, and the part after it continuously untill all the seperator finishes. If the separator is not found, return string s. It works like split() combined with partition()

string multi-partitioning (Python)

2010-03-26T20:03:59-07:00

Python recipe 577017 by Michael Grünewald (partition, string). Revision 6.

Works like the partition method of strings in Python2.5+, but has support for more than one delimiter.

Better description by Gabriel Genellina:

Split the string at separator boundaries. The separators are searched from left to right, in the same order specified, and one after another. Unlike partition, all of them must be present (else ValueError is raised). Only one split per separator occurrence is done. Returns a list containing one more element than separators were given: first, text from beginning of the string up to (but not including) the first separator; the first separator itself; text between the first separator and the second one; the second separator; and so on. The last element contains all text following the last separator.

Simple reverse converter of unicode code points string (Python)

2009-09-22T20:02:32-07:00

Python recipe 576909 by Ryan (code, points, prefix, reverse, str, string, u, unicode). Revision 4.

It's a simple recipe to convert a str type string with pure unicode code point (e.g string = "\u5982\u679c\u7231" ) to an unicode type string. Actually, this method has the same effect with 'u' prefix. But differently, it allows you to pass a variable of code points string as well as a constant one.

Convert datetime in python to user friendly representation. (Python)

2009-08-15T01:00:03-07:00

Python recipe 576880 by Jai Vikram Singh Verma (ago, datetime, parse, representation, string, user_friendly).

A small contribution to the developer community.

This module caters to the need of developers who want to put date & time of post in terms like
"X days, Y hrs ago", "A hours B mins ago", etc. in their applications rather then a basic timestamp
like "2009-08-15 03:03:00". Additionally it also
provides since epoch for a given datetime.

It takes in a Python datetime object as an input
and provides a fancy datetime (as I call it) and
the seconds since epoch.