Pandas numpy compare two array of different size

Question

I have 2 arrays, one of 1000 values and the other one of 8448 values. I'm tryig to count the number of identique values in the two dataframe.

t1 = dfRight['X'].values
t2 = dfLeft['X'].values
t1 == t2

But it return "False", someone know an easy ways to do this please ?

MaxU - stand with Ukraine · Accepted Answer · 2017-07-13 13:43:21Z

5

Try this:

np.intersect1d(t1, t2)

or using Pandas:

dfRight.merge(dfLeft, on='X')

Data:

In [79]: dfRight
Out[79]:
   X
0  1
1  3
2  5
3  7

In [80]: dfLeft
Out[80]:
   X
0  1
1  2
2  3
3  4
4  5
5  6
6  7
7  8
8  9

Merging:

In [82]: dfRight.merge(dfLeft, on='X')
Out[82]:
   X
0  1
1  3
2  5
3  7

Counting:

In [81]: dfRight['X'].isin(dfLeft['X']).sum()
Out[81]: 4

answered Jul 13, 2017 at 13:43

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