Creating for loop until list.length

25

I'm reading about for loops right now, and I am curious if it's possible to do a for loop in Python like in Java.

Is it even possible to do something like

for (int i = 1; i < list.length; i++)

and can you do another for loop inside this for loop ?

Thanks

This question is tagged with python list for-loop

~ Asked on 2013-01-26 01:28:17

The Best Answer is


49

In Python you can iterate over the list itself:

for item in my_list:
   #do something with item

or to use indices you can use xrange():

for i in xrange(1,len(my_list)):    #as indexes start at zero so you 
                                    #may have to use xrange(len(my_list))
    #do something here my_list[i]

There's another built-in function called enumerate(), which returns both item and index:

for index,item in enumerate(my_list):
    # do something here

examples:

In [117]: my_lis=list('foobar')

In [118]: my_lis
Out[118]: ['f', 'o', 'o', 'b', 'a', 'r']

In [119]: for item in my_lis:
    print item
   .....:     
f
o
o
b
a
r

In [120]: for i in xrange(len(my_lis)):
    print my_lis[i]
   .....:     
f
o
o
b
a
r

In [122]: for index,item in enumerate(my_lis):
    print index,'-->',item
   .....:     
0 --> f
1 --> o
2 --> o
3 --> b
4 --> a
5 --> r

~ Answered on 2013-01-26 01:31:31


7

Yes you can, with range [docs]:

for i in range(1, len(l)):
    # i is an integer, you can access the list element with l[i]

but if you are accessing the list elements anyway, it's more natural to iterate over them directly:

for element in l:
   # element refers to the element in the list, i.e. it is the same as l[i]

If you want to skip the the first element, you can slice the list [tutorial]:

for element in l[1:]:
    # ...

can you do another for loop inside this for loop

Sure you can.

~ Answered on 2013-01-26 01:31:18


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