Python Equivalent Of The R Operator "%in%"

What is the python equivalent of this in operator? I am trying to filter down a pandas database by having rows only remain if a column in the row has a value found in my list. I

Solution 1:

Pandas comparison with R docs are here.

s <- 0:4
s %in%c(2,4)

The isin() method is similar to R %in% operator:

In [13]: s = pd.Series(np.arange(5),dtype=np.float32)

In [14]: s.isin([2, 4])
Out[14]: 
0False1False2True3False4True
dtype: bool

Solution 2:

FWIW: without having to call pandas, here's the answer using a for loop and list compression in pure python

x= [2, 3, 5] 
y= [1, 2, 3]

# for loopfor i in x: [].append(iiny)Out: [True, True, False]


# list comprehension
[iinyforiinx]

Out: [True, True, False]

Solution 3:

If you want to use only numpy without panads (like a use case I had) then you can:

import numpy as np

x = np.array([1, 2, 3, 10])
y = np.array([10, 11, 2])
np.isin(y, x)

This is equivalent to:

c(10, 11, 2) %in% c(1, 2, 3, 10)

Note that the last line will work only for numpy >= 1.13.0, for older versions you'll need to use np.in1d.

Solution 4:

As others indicate, in operator of base Python works well.

myList = ["a00", "b000", "c0"]

"a00" in myList
# True"a" in myList
# False