CODEWITHSUNDEEP
pythonpandas
Demetri Pananos
Demetri Pananos

Reputation: 7404

Using 'or' in a Dataframe

I can find where my DataFrame has ALEX or KIM in the name column by using 

df.query('Name=="ALEX" or Name=="KIM"')



        Name    Gender
4556    ALEX    ('male', 'female')
4560    KIM ('female', 'male')

However, when I use df[df.Name==('ALEX' or 'KIM')], the following is returned:

        Name    Gender
4556    ALEX    ('male', 'female')

and when I use df[df.Name==('ALEX' and 'KIM')] the following is returned:

        Name    Gender
4560    KIM ('female', 'male')

So, i) How can I find where Name is ALEX or KIM in a purely pythonic way, and ii) why does the logic behave the way it does for the last two examples?

Upvotes: 1

Views: 105

Answers (1)

user2285236
user2285236

Reputation:

The element-wise or operator in pandas is |. or operator does not work because it makes a comparison against the whole series df.Name (thus returns a single value). You can use the element-wise operator like this:

df[(df.Name == "ALEX") | (df.Name == "KIM")]

Or, you can use the isin method:

df[df.Name.isin(["ALEX", "KIM"])]

Upvotes: 4

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