How do I call a function twice or more times consecutively

Question

Is there a short way to call a function twice or more consecutively in Python  For example   do   do   do     maybe like   3 do

User · Accepted Answer

I would   for   in range 3       do     The   is convention for a variable whose value you don t care about   You might also see some people write    do   for   in range 3     however that is slightly more expensive because it creates a list containing the return values of each invocation of do    even if it s None   and then throws away the resulting list  I wouldn t suggest using this unless you are using the list of return values

User · Answer

My two cents   from itertools import repeat   list repeat f    x      for pure f  f   for f in repeat f  x      for impure f

User · Answer

You could define a function that repeats the passed function N times    def repeat fun times  f       for i in range times   f     If you want to make it even more flexible  you can even pass arguments to the function being repeated   def repeat fun times  f   args       for i in range times   f  args    Usage    gt  gt  gt  def do          print  Doing        gt  gt  gt  def say s         print s       gt  gt  gt  repeat fun 3  do  Doing Doing Doing  gt  gt  gt  repeat fun 4  say   Hello    Hello  Hello  Hello  Hello

User · Answer

Here is an approach that doesn t require the use of a for loop or defining an intermediate function or lambda function  and is also a one-liner   The method combines the following two ideas    calling the iter   built-in function with the optional sentinel argument  and using the itertools recipe for  advancing an iterator n steps  see the recipe for consume       Putting these together  we get    next islice iter do  object     3  3   None     The idea to pass object   as the sentinel comes from this accepted Stack Overflow answer    And here is what this looks like from the interactive prompt    gt  gt  gt  def do          print  called         gt  gt  gt  next itertools islice iter do  object     3  3   None  called called called

User · Answer

from itertools import repeat  starmap  results   list starmap do  repeat     3      See the repeatfunc recipe from the itertools module that is actually much more powerful  If you need to just call the method but don t care about the return values you can use it in a for loop   for   in starmap do  repeat     3    pass   but that s getting ugly

User · Answer

You can use itertools repeat with operator methodcaller to call the   call   method of the function N times  Here is an example of a generator function doing it   from itertools import repeat from operator import methodcaller   def call n times function  n       yield from map methodcaller    call      repeat function  n     Example of usage   import random from functools import partial  throw dice   partial random randint  1  6  result   call n times throw dice  10  print list result      6  3  1  2  4  6  4  1  4  6

User · Answer

A simple for loop   for i in range 3     do     Or  if you re interested in the results and want to collect them  with the bonus of being a 1 liner   vals    do   for   in range 3

User · Answer

You may try while loop as shown below   def do1          Do something  def do2 x       while x  gt  0          do1           x -  1  do2 5    Thus make call the do1 function 5 times

User · Answer

Three more ways of doing so    I  I think using map may also be an option  though is requires generation of an additional list with Nones in some cases and always needs a list of arguments   def do        print  hello world   l map lambda x  do    range 10      II  itertools contain functions which can be used used to iterate through other functions as well https   docs python org 2 library itertools html   III  Using lists of functions was not mentioned so far I think  and it is actually the closest in syntax to the one originally discussed     it  do  10  f   for f in it    Or as a one liner    f   for f in  do  10

[python] How do I call a function twice or more times consecutively?

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