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Check if item is in an array / list

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How do you check if an ArrayList contains another ArrayList?

ArrayList contains() method in Java is used for checking if the specified element exists in the given list or not. Returns: It returns true if the specified element is found in the list else it returns false.

How do you check if a list contains an object Java?

Check using the Stream API (Java 8+) We can use the Stream API to find whether the list contains an object with a specific value for the name attribute. list. stream(). anyMatch(o -> o.


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.


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

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)

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