Python:Strings - Revision history

Hdridder: /* Using format(string) */

2025-10-17T13:40:04Z

Using format(string)

← Older revision		Revision as of 13:40, 17 October 2025
Line 81:		Line 81:
	</syntaxhighlight>		</syntaxhighlight>

	;{~~[field]~~<nowiki>:</nowiki>formatspec}		;{value<nowiki>:</nowiki>formatspec}
	:The format can be specified after the (optional) fieldnumber.		:The format can be specified after the (optional) fieldnumber.

	;[[fill]align][sign][#][0][width][grouping_option][.precision][type]		;<code>[[fill]align][sign][#][0][width][grouping_option][.precision][type]</code>
	:Generic format specification. Anything not needed can be left out [https://www.ranblog.com/blog/python-format/#groupingoption].		:Generic format specification. Anything not needed can be left out [https://www.ranblog.com/blog/python-format/#groupingoption].
	:e.g. "{:07d}".format(5) fill out with 0 in front to 7 digits -> '0000005'		:e.g. "{:07d}".format(5) fill out with 0 in front to 7 digits -> '0000005'
	::"{:010.6f}".format(5.7647) floating point with precision 6 and total width 10 left fill with 0 -> '005.764700'		::"{:010.6f}".format(5.7647) floating point with precision 6 and total width 10 left fill with 0 -> '005.764700'
	::"{:10,.2f}".format(12345.7647) floating point with precision 2,total width 10 and comma as thousand separator -> ' 12,345.76'		::"{:10,.2f}".format(12345.7647) floating point with precision 2,total width 10 and comma as thousand separator -> ' 12,345.76'
	::"{:#=+15_.3f}".format(10000) # as padding, padding after sign, always show sign, _ as thousand separator, floating point with precision 3 -> +####10_000.000		::"{:#=+15_.3f}".format(10000) # as padding, padding after sign, always show sign, 15 characters in total, _ as thousand separator, floating point with precision 3 -> +####10_000.000

	{\| class="wikitable"		{\| class="wikitable"

Hdridder: /* Basics */

2025-10-16T12:46:22Z

Basics

← Older revision		Revision as of 12:46, 16 October 2025
Line 5:		Line 5:
	;str1 + str2		;str1 + str2
	:Return concatenation of str1 and str2		:Return concatenation of str1 and str2

	;str1 += str2		;str1 += str2
	:Append str2 to str1		:Append str2 to str1

	;str1 * 3		;str1 * 3
	:Return str1 3 times		:Return str1 3 times
			;str(<anything>)
			:Convert <anything> to a string
			:NOTE: <code>str(Decimal(9.0))</code> has a different result (<code>'9'</code>) than <code>str(Decimal('9.0'))</code> (<code>'9.0'</code>) as the specified precision will be in the string too. Floats (9.0) are not exact enough to do this.

	=Formatting=		=Formatting=

Hdridder: /* Regular Expressions (regexp) */

2025-07-07T14:24:51Z

Regular Expressions (regexp)

← Older revision		Revision as of 14:24, 7 July 2025
Line 156:		Line 156:

	==[[Regular Expressions]] (regexp)==		==[[Regular Expressions]] (regexp)==
			Cheatography has a nice overview[https://cheatography.com/mutanclan/cheat-sheets/python-regular-expression-regex/].
	;import re		;import re
	:The re module provides Perl-like [[Regular Expressions]] matching for string and byte objects.		:The re module provides Perl-like [[Regular Expressions]] matching for string and byte objects.

Hdridder: /* Match Objects */

2025-07-04T10:47:28Z

Match Objects

← Older revision		Revision as of 10:47, 4 July 2025
Line 194:		Line 194:

	===Match Objects===		===Match Objects===
	;match .group()		;match.group()
	;match .group(0)		;match.group(0)
	:The matched string in match object 'mo'		:The matched string in match object 'match'
	;match .group(1)		;match.group(1)
	:First submatch in the matched string in 'mo'. The first match is the first ( in the expression.		:First submatch in the matched string in 'match'. The first match is the first ( in the expression.
	;match .start()		;match.start()
	:The start position of the matched string in 'mo'		:The start position of the matched string in 'match'
	;match .end()		;match.end()
	:The end position of the matched string in 'mo'		:The end position of the matched string in 'match'
	;match .span()		;match.span()
	:Tuple with start and end position of the matched string in 'mo'		:Tuple with start and end position of the matched string in 'match'

	===Search Modifieres===		===Search Modifieres===

Hdridder: /* Basic */

2024-07-21T08:30:35Z

Basic

← Older revision		Revision as of 08:30, 21 July 2024
Line 17:		Line 17:
	;str1.replace(old,new[,cnt])		;str1.replace(old,new[,cnt])
	:Return str1 with old replaced by new (cnt times).		:Return str1 with old replaced by new (cnt times).
			:For more complex replacements, like regular expressions, see re.sub below.

	;str1.strip(<chars>)		;str1.strip(<chars>)

Hdridder: /* Basic */

2024-07-09T06:07:52Z

Basic

← Older revision		Revision as of 06:07, 9 July 2024
Line 22:		Line 22:

	;str1.rstrip('\r\n')		;str1.rstrip('\r\n')
			:Return str1 with all newline characters (windows, mac or unix) stripped from the end of str1, like perl 'chomp' does.
	;str1.lstrip('<char>')		;str1.lstrip('<char>')
	~~:Return str1 with all newline characters (windows, mac or unix) stripped from the end of str1, like perl 'chomp' does.~~
	:lstrip removes characters from the beginning of str1		:lstrip removes characters from the beginning of str1
	:~~Without character specification~~ all whitespaces ~~are removed.~~		:Both rstrip and lstrip remove all whitespaces if nothing is specified

	;str1.upper() str1.lower() str1.title()		;str1.upper() str1.lower() str1.title()
	:Return str1 in ~~upppercase~~, lowercase or with only all first characters in uppercase		:Return str1 in uppercase, lowercase or with only all first characters in uppercase

	;str1.join(list)		;str1.join(list)

Hdridder: /* Regular Expressions (regexp) */

2024-02-20T15:41:11Z

Regular Expressions (regexp)

← Older revision		Revision as of 15:41, 20 February 2024
Line 167:		Line 167:
	:NOTE1: str1 remains unchanged.		:NOTE1: str1 remains unchanged.
	:NOTE2: re.sub is much more expensive than string.replace		:NOTE2: re.sub is much more expensive than string.replace
	:NOTE3: if you want to use search modifiers like DOTALL you must use the object from re.compile.		:NOTE3: if you want to use search modifiers like DOTALL you must use 'flags=<modifier>' or the object from re.compile.

	;re.split(regexp,str1,max)		;re.split(regexp,str1,max)

Hdridder: /* Regular Expressions (regexp) */

2023-12-06T08:53:11Z

Regular Expressions (regexp)

← Older revision		Revision as of 08:53, 6 December 2023
Line 165:		Line 165:
	;re.sub(regexp,new,str1)		;re.sub(regexp,new,str1)
	:Return str1 with all parts matching regexp replaced with new.		:Return str1 with all parts matching regexp replaced with new.
	:~~NOTE~~: str1 remains unchanged.		:NOTE1: str1 remains unchanged.
	:NOTE2: re.sub is much more expensive than string.replace		:NOTE2: re.sub is much more expensive than string.replace
	:NOTE3: if you want to use search modifiers like DOTALL you must use the object from re.compile.		:NOTE3: if you want to use search modifiers like DOTALL you must use the object from re.compile.
Line 181:		Line 181:
	;matchlist = re.findall(regexp,str1)		;matchlist = re.findall(regexp,str1)
	:Find all occurrences of 'regexp' in 'str1'. Return a [[Python:DataTypes#List\|list]] of strings.		:Find all occurrences of 'regexp' in 'str1'. Return a [[Python:DataTypes#List\|list]] of strings.
	:~~NOTE~~: When using a subexpression findall returns a list of tuples for the subexpression matches.		:NOTE1: This may be very slow on regular expressions with multiple '.*?' clauses. Use finditer to prevent this.
	:Use finditer or, ~~in this example~~ to get the first subexpression matched ~~(group(1))~~:		:NOTE2: When using a subexpression findall returns a list of tuples for the subexpression matches.
			::Use finditer or, below solution to get the first subexpression matched:
	<syntaxhighlight lang=python>		<syntaxhighlight lang=python>
	ListOfTuples = re.findall('(regexppart1 (subexpression1) regexppart2)',str1)		ListOfTuples = re.findall('(regexppart1 (subexpression1) regexppart2)',str1)

Hdridder: /* Regular Expressions (regexp) */

2023-12-05T08:33:03Z

Regular Expressions (regexp)

← Older revision		Revision as of 08:33, 5 December 2023
Line 156:		Line 156:
	==[[Regular Expressions]] (regexp)==		==[[Regular Expressions]] (regexp)==
	;import re		;import re
	:The re ~~modules~~ provides Perl-like [[Regular Expressions]] matching for string and byte objects~~. The re module is standard available (no installation needed)~~.		:The re module provides Perl-like [[Regular Expressions]] matching for string and byte objects.

	;re1 = re.compile(regexp)		;re1 = re.compile(regexp)
	:Create regular expression object to use for matching. This is more efficient if the regular expression in used several times in a program.		:Create regular expression object to use for matching. This is more efficient if the regular expression is used several times in a program.

	'''NOTE: In all examples below regexp can be replaced by the object from re.compile'''		'''NOTE: In all examples below regexp can be replaced by the object from re.compile'''
Line 167:		Line 167:
	:NOTE: str1 remains unchanged.		:NOTE: str1 remains unchanged.
	:NOTE2: re.sub is much more expensive than string.replace		:NOTE2: re.sub is much more expensive than string.replace
	:NOTE3: if you want to use search modifiers like DOTALL you ~~have to~~ use the object from re.compile.		:NOTE3: if you want to use search modifiers like DOTALL you must use the object from re.compile.

	;re.split(regexp,str1,max)		;re.split(regexp,str1,max)

Hdridder: /* Using format */

2023-02-28T09:23:07Z

Using format

← Older revision		Revision as of 09:23, 28 February 2023
Line 49:		Line 49:
	:Replace tabs by 'size' number of spaces.		:Replace tabs by 'size' number of spaces.

	==Using format==		==Using format(string)==
	;str1.format(values)		;str1.format(values)
	:Fill in 'values' in str1-fields ({}). By numbering the fields they can be in a different order than the values.		:Fill in 'values' in str1-fields ({}). By numbering the fields they can be in a different order than the values.
Line 125:		Line 125:
	\|e\|\|Exponent		\|e\|\|Exponent
	\|-		\|-
	\|g\|\|Python chooses between decimal, float or exponent		\|g\|\|Python chooses between decimal, float or exponent with lowercase e
			\|-
			\|G\|\|Python chooses between decimal, float or exponent with capital E
	\|}		\|}