alec_djinn alec_djinn - 1 month ago 4
Python Question

How to check if any value of a column is in a range in Pandas?

I have a DataFrame and I would like to check if any of the values (v) of a column satisfy

x<=v<=y
.

equal = any(df['columnX'] == value) # No problems here
in_between = any(x <= df['columnX'] <= y) # ValueError :/


The error I get is
ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().
But I am using
any()
already!

So what's the problem here? Why does it work with
==
but not with
x<=v<=y
?

Answer

Use between to do this, it also supports whether the range values are included or not via inclusive arg:

In [130]:
s = pd.Series(np.random.randn(5))
s

Out[130]:
0   -0.160365
1    1.496937
2   -1.781216
3    0.088023
4    1.325742
dtype: float64

In [131]:
s.between(0,1)

Out[131]:
0    False
1    False
2    False
3     True
4    False
dtype: bool

You then call any on the above:

In [132]:
s.between(0,1).any()

Out[132]:
True
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