Python:Functions - Revision history

Hdridder: /* Build in functions */

2026-04-28T09:50:39Z

Build in functions

← Older revision		Revision as of 09:50, 28 April 2026
Line 112:		Line 112:
	import decimal		import decimal
	value = str(valuein)		value = str(valuein)
	if digits == None:		if digits is None:
	try:		try:
	digits = len(value.split('.')[1])		digits = len(value.split('.')[1])

Hdridder: /* Other often used functions */

2025-12-11T10:14:38Z

Other often used functions

← Older revision		Revision as of 10:14, 11 December 2025
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	;all(<object>)		;all(<object>)
	:True if all elements of <object> are true (have a value)		:True if all elements of <object> are true (have a value)

			=Resursive functions=
			In resursive functions you should update the objects to return, not create new ones. Use augmented assignment (+=).

	=Other often used functions=		=Other often used functions=

Hdridder: /* Anonymous functions(lambda) */

2025-11-12T13:40:20Z

Anonymous functions(lambda)

@@ Line 73: / Line 73: @@
 =Anonymous functions(lambda)=
 lambda defines an anonymous function.
 =Build in functions=

Hdridder: /* Boolean functions */

2025-11-12T13:07:04Z

Boolean functions

← Older revision		Revision as of 13:07, 12 November 2025
Line 127:		Line 127:
	;isfile(filename)		;isfile(filename)
	:If a file exists		:If a file exists
	;any(~~alist~~)
			;any(<object>)
	:If any of the elements is True (any iterateble will do)		:If any of the elements is True (any iterateble will do)
	;any(x in alist for x in aset)		;any(x in alist for x in aset)
	:If any of the elements of list are in set		:If any of the elements of list are in set
	;all()		;all(<object>)
	:If all of ~~the elements~~ are true		:True if all elements of <object> are true (have a value)

	=Other often used functions=		=Other often used functions=

Hdridder: /* Build in functions */

2025-11-12T13:05:34Z

Build in functions

← Older revision		Revision as of 13:05, 12 November 2025
Line 120:		Line 120:
	;repr(object)		;repr(object)
	:Return a string representation of an object. str for the informal representation (just make it printable), repr for the formal representation (more formating??)		:Return a string representation of an object. str for the informal representation (just make it printable), repr for the formal representation (more formating??)

	~~;all(object)~~
	~~:True if all elements of <object> are true (have a value)~~

	=Boolean functions=		=Boolean functions=

Hdridder: /* Build in functions */

2025-11-12T13:05:11Z

Build in functions

← Older revision		Revision as of 13:05, 12 November 2025
Line 120:		Line 120:
	;repr(object)		;repr(object)
	:Return a string representation of an object. str for the informal representation (just make it printable), repr for the formal representation (more formating??)		:Return a string representation of an object. str for the informal representation (just make it printable), repr for the formal representation (more formating??)

			;all(object)
			:True if all elements of <object> are true (have a value)

	=Boolean functions=		=Boolean functions=

Hdridder at 07:19, 11 November 2025

2025-11-11T07:19:35Z

← Older revision		Revision as of 07:19, 11 November 2025
Line 4:		Line 4:
	:Return name of current function		:Return name of current function

	;~~You can pass~~ a function-name as ~~parameter~~		;eval(functionnameasstring)()
			:Convert a function name as string to a function call
			:WARNING: Make sure you have control over the string provided, you may call anything this way.


			=Passing arguments=

			If an argument is a mutable object it is passed by reference. So when you modify the object in the function, the change there in the outside world too.
			Immutable objects are passed by value. You cannot change the object, you have to return the new one.

	<syntaxhighlight lang='python'>		<syntaxhighlight lang='python'>
	def main():		def main():
	~~outcome~~ = ~~function1~~(~~function2~~,~~inpar2 = <value>~~)		aInt = 1
			aList = ['a']
			bInt = function(aInt, aList)
			print(aInt, bInt, aList) # This will print: "1 6 ['a', 'something']"
	return		return

	def ~~function1~~ (~~functiontocall~~, ~~inpar2 = <defaultvalue>~~):		def function (a, b):
	~~result = functiontocall(inpar2)~~		# a is a new integer object
	~~return result~~		# b is a reference to the aList object.
			a += 5
	~~def function2~~ (~~inpar~~):		b.append('something')
	~~codeblock~~		return a
	return ~~result~~

	main()		main()
	</syntaxhighlight>		</syntaxhighlight>

	~~;eval(functionnameasstring)()~~
	~~:Convert a function name as string to a function call~~
	~~:WARNING: Make sure you have control over the string provided, you may call anything this way.~~


	~~=Self defined functions=~~

	Arguments are positional but can be passed by keyword too.		Arguments are positional but can be passed by keyword too.
Line 49:		Line 53:
	:Take any number of keyword arguments and put them in the [[Python:DataTypes#Dictionary_or_dict\|dict]] kwargs		:Take any number of keyword arguments and put them in the [[Python:DataTypes#Dictionary_or_dict\|dict]] kwargs


			;You can pass a function-name as parameter

			<syntaxhighlight lang='python'>
			def main():
			outcome = function1(function2,inpar2 = <value>)
			return

			def function1 (functiontocall, inpar2 = <defaultvalue>):
			result = functiontocall(inpar2)
			return result

			def function2 (inpar):
			codeblock
			return result

			main()
			</syntaxhighlight>

	=Anonymous functions(lambda)=		=Anonymous functions(lambda)=

Hdridder: /* Build in functions */

2025-01-27T10:37:55Z

Build in functions

← Older revision		Revision as of 10:37, 27 January 2025
Line 69:		Line 69:
	;round(x,y)		;round(x,y)
	:Round x to y decimals, y defaults to 0		:Round x to y decimals, y defaults to 0
	;BEWARE; In python 3x rounding does not work 'As taught in school'[https://stackoverflow.com/questions/10825926/python-3-x-rounding-behavior] but ~~rounding~~ half to even[https://en.wikipedia.org/wiki/Rounding#Round_half_to_even].		;BEWARE; In python 3x rounding does not work 'As taught in school'[https://stackoverflow.com/questions/10825926/python-3-x-rounding-behavior] but rounds half to even[https://en.wikipedia.org/wiki/Rounding#Round_half_to_even].
	Use this to implement 'As taught in school' by overwriting the round() function.		Use this to implement 'As taught in school' by overwriting the round() function.

Hdridder: /* Build in functions */

2024-10-29T10:46:32Z

Build in functions

← Older revision		Revision as of 10:46, 29 October 2024
Line 73:		Line 73:

	<syntaxhighlight lang=python>		<syntaxhighlight lang=python>
	def round(~~value~~, digits=None):		def round(valuein, digits=None):
	~~from~~ decimal ~~import Decimal, ROUND_HALF_UP~~		import decimal
			value = str(valuein)
	if digits == None:		if digits == None:
	digits = len(value.split('.')[1])		try:
			digits = len(value.split('.')[1])
			except IndexError:
			digits = 0
	formatstring = '1.' + '1' * digits		formatstring = '1.' + '1' * digits
	~~return~~ Decimal~~(str~~(value)).quantize(Decimal(formatstring), rounding=ROUND_HALF_UP)		try:
			result = decimal.Decimal(value).quantize(decimal.Decimal(formatstring), rounding=decimal.ROUND_HALF_UP)
			except decimal.InvalidOperation:
			result = valuein
			return result
	</syntaxhighlight>		</syntaxhighlight>

Hdridder: /* Build in functions */

2024-09-24T14:31:00Z

Build in functions

← Older revision		Revision as of 14:31, 24 September 2024
Line 73:		Line 73:

	<syntaxhighlight lang=python>		<syntaxhighlight lang=python>
	def round(value, digits=0):		def round(value, digits=None):
	from decimal import Decimal, ROUND_HALF_UP		from decimal import Decimal, ROUND_HALF_UP
			if digits == None:
			digits = len(value.split('.')[1])
	formatstring = '1.' + '1' * digits		formatstring = '1.' + '1' * digits
	return Decimal(str(value)).quantize(Decimal(formatstring), rounding=ROUND_HALF_UP)		return Decimal(str(value)).quantize(Decimal(formatstring), rounding=ROUND_HALF_UP)