CODEWITHSUNDEEP
pythonlisttuples
Mark K
Mark K

Reputation: 9378

Filtering tuples in a list

(Python 2.7, Windows)

hello all, I have a list containing tuples and I want to filter out the "(0,0,35)":

a_list = [(0,0,35), (0,0,35), (9,12,12), (0,0,35), (5,12,6)]

for element in a_list:
    if element is not "(0,0,35)":
        print element

it does't work.

Can you show me the right way? thanks.

Upvotes: 0

Views: 116

Answers (3)

Thibaut
Thibaut

Reputation: 1408

This doesn't work because you are testing against the string "(0,0,35)" which is not the same as the tuple (0,0, 35). This should work:

a_list = [(0,0,35), (0,0,35), (9,12,12), (0,0,35), (5,12,6)]

for element in a_list:
    if element != (0,0,35):
        print element

A better solution would probably be to construct the filtered list using a list comprehension:

a_list = [(0,0,35), (0,0,35), (9,12,12), (0,0,35), (5,12,6)]
filtered_list = [e for e in a_list if e != (0,0,35)]

Upvotes: 3

Hackaholic
Hackaholic

Reputation: 19771

this should work:

[ x for x in a_list if x != (0,0,35) ]

demo:

>>> (1,2,3) == '(1,2,3)'
False
>>> str((1,2,3)) == '(1,2,3)'
False
>>> (1,2,3) == (1,2,3)
True

even if you force it to str ti will result in false

Upvotes: 1

A.J. Uppal
A.J. Uppal

Reputation: 19284

This will not work, because tuples cannot be represented as strings. 

>>> (0, 0, 35) == "(0, 0, 35)"
False
>>>

Also, use != instead of is not because == tests for equality (the prefix ! tests for inequality), but is tests for the id being the same (the not checks for the id not being the same).

>>> x = (0, 0, 35)
>>> x is (0, 0, 35)
False
>>> x == (0, 0, 35)
True
>>> id(x)
4299863136
>>> id((0, 0, 35))
4299863216
>>>

Try this:

a_list = [(0,0,35), (0,0,35), (9,12,12), (0,0,35), (5,12,6)]

for element in a_list:
    if element != (0,0,35):
        print element

Upvotes: 2

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