CODEWITHSUNDEEP
python
Fillethacker Ranjid
Fillethacker Ranjid

Reputation: 91

Create 20 empty lists with for loop

I need 20 empty lists with the letters from a to t.My code right now is:

    list_a = []
    list_b = []
    list_c = []
    ...

creates me this:

    list_a[]
    list_b[]
    list_c[]
    ...

can i do this with a simple for loop somehow?? This is what i have right now. I can loop the letters from a to t and print them out

    for i in range(ord('a'), ord('t') +1):
        print i

output:

    a
    b
    c
    d
    e
    ...

and so on...

I need it for that script i wrote.I have 2 empty lists for testing.It's working fine .But now i need to play with 20 lists

from os import system

    list_a = []
    list_b = []
    list_c = [1, 2, 3, 4, 5]


while True:
    system("clear")

    print "\nList A ---> ", list_a
    print "List B ---> ", list_b
    print "List C ---> ", list_c

    item = input ("\n?> ")

    place = [list_a, list_b, list_c]
    place_name = ["List A", "List B", "List C"]

    for i ,a in zip(place, place_name):
        if item in i:
             print "\nItem", item, "--->", a
             print "\n\n1) List A"
             print "2) List B"
             print "3) List C\n"

             target = input("move to ---> ")
             target = target - 1
             target = place[target]

             i.remove(item)
             target.append(item)

             print "\nItem moved"

             break

     raw_input()

Upvotes: 1

Views: 1232

Answers (4)

mirk
mirk

Reputation: 5530

You can use exec to interpret generated code.

for i in xrange(ord('a'),ord('t')+1):
    exec("list_%c=[]" % i)
print locals()

exec should not be overused, but here it seems to fit well.

Upvotes: 1

onemouth
onemouth

Reputation: 2277

Use locals() function

>>> names = locals()
>>> for i in xrange(ord('c'), ord('t')+1):
>>>   names['list_%c' % i] = []

>>> list_k
    []

Upvotes: 1

Owen
Owen

Reputation: 1736

You can make a list of lists like this my_list = [[] for i in range (20)].

If you want to use a for-loop, i.e. not using python's awesome list-comprehension, then you can do so as follows:

my_list = []
for i in range (20):
    my_list.append ([])

Upvotes: 1

Tim Pietzcker
Tim Pietzcker

Reputation: 336408

Use a different approach:

mylist = {letter:[] for letter in "abcdefghijklmnopqrst"}

Now you can access mylist["a"] through mylist["t"]

Upvotes: 5

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