Python | Pandas Index.isin ()

Index.isin() Pandas Index.isin() returns a boolean array in which the index values are in values. compute a boolean array of whether each index value is in the passed set of values. The returned boolean array has the same length as the index.

Syntax: Index.isin (values, level = None)

Parameters:
values: [set or list-like] Sought values.
level: Name or position of the index level to use ( if the index is a MultiIndex).

Returns: NumPy array of boolean values.

Example # 1: Use Index.isin () to check if the index value is present in the passed list of values.

# import pandas as pd import pandas as pd   # Create index idx = pd.Index ([ ’Labrador’ , ’Beagle’ , ’ Mastiff’ , ’Lhasa’ , ’Husky’ , ’ Beagle’ ])   # Print index idx

Exit:

Now we will find out if index marks are present in the passed list.

# Pass a list containing with two values ​​against # to which the index tags will be matched idx.isin ([ ’Lhasa’ , ’ Mastiff’ ])

Exit:

The function returned an array object of the same size as the index.  True means that the index mark was present in the passed list object, and False means that the index mark was not present in the passed list object.

Example # 2: Use Index.isin () to check if MultiIndex tags are present in the passed list.

# import pandas as pd import pandas as pd   # Create MutiIndex midx = pd.MultiIndex.from_arrays ([[ ’Mon’ , ’Tue’ , ’Wed’ , ’Thr’ ],   [ 10 , 20 , 30 , 40 ]], names = ( ’Days’ , ’ Target’ ))   # Print MultiIndex midx

Output:

Now we will check if the tags in the MultiInndex are present in the passed list or not.

# check if there are tags in the list or not midx.isin ([ ’Tue’ , ’Wed’ , ’ Fri’ , ’ Sat’ ], level = ’Days’ )

Output:

As we can see from the output, the function returned an array object, the size of which matches the size of the selected MultiIndex level.  True means that the index mark was present in the passed list object, and False means that the index mark was not present in the passed list object.