If I've got an array of strings, can I check to see if a string is in the array without doing a for loop? Specifically, I'm looking for a way to do it within an if statement, so something like this:
if [check that item is in array]:
user1767754
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asked Jun 28, 2012 at 19:39
SomeKittensSomeKittens
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Assuming you mean "list" where you say "array", you can do
if item in my_list:
# whatever
This works for any collection, not just for lists. For dictionaries, it checks whether the given key is present in the dictionary.
answered Jun 28, 2012 at 19:40
Sven MarnachSven Marnach
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I'm
also going to assume that you mean "list" when you say "array." Sven Marnach's solution is good. If you are going to be doing repeated checks on the list, then it might be worth converting it to a set or frozenset, which can be faster for each check. Assuming your list of strs is called subjects:
subject_set = frozenset[subjects]
if query in subject_set:
# whatever
Mark Ransom
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answered Jun 28, 2012 at 19:43
Michael HoffmanMichael Hoffman
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Use a lambda function.
Let's say you have an array:
nums = [0,1,5]
Check whether 5 is in nums in Python 3.X:
[len[list[filter [lambda x : x == 5, nums]]] > 0]
Check whether 5 is in nums in Python 2.7:
[len[filter [lambda x : x == 5, nums]] > 0]
This solution is more robust. You can now check whether any number satisfying a certain condition is in your array nums.
For example, check whether any number that is greater than or equal to 5 exists in nums:
[len[filter [lambda x : x >= 5, nums]] > 0]
T.Woody
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answered Sep 11, 2017 at 16:33
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You have to use .values for arrays. for example say you have dataframe which has a column name ie, test['Name'], you can do
if name in test['Name'].values :
print[name]
for a normal list you dont have to use .values
slfan
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answered Nov 25, 2017 at 11:06
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You can also use the same syntax for an array. For example, searching within a Pandas series:
ser = pd.Series[['some', 'strings', 'to', 'query']]
if item in ser.values:
# do stuff
answered Dec 11, 2015 at 23:32
BCRBCR
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