python - See if a value exists in a DataFrame

Question

In Python to check if a value is in a list you can simply do the following:

>>>9 in [1,2,3,6,9]
True

I would like to do the same for a Pandas DataFrame but unfortunately Pandas does not recognise that notation:

>>>import pandas as pd
>>>df = pd.DataFrame([[1,2,3,4],[5,6,7,8]],columns=["a","b","c","d"])
   a  b  c  d
0  1  2  3  4
1  5  6  7  8
>>>7 in df
False

How would I achieve this using Pandas DataFrame without iterating through each column/row or anything complicated?

Answer 1

Basically you have to check the matrix without the schema, so:

 7 in df.values

x in df checks if x is in the columns:

for x in df:
    print x,

out: a b c d