[Python] How to get the number of the row that contains a specific value in the given column?

I need to get the number of the row that contains a specific value in the given column. It is guaranteed that such value exists in the column and in a unique row.

My attempt:

import pandas as pd
pos = pd.DataFrame(columns=['id', 'pred'])
pos.loc[1,'id'] = [4, 4, 4]
pos.loc[2,'id'] = [2, 3, 3]
pos.loc[3,'id'] = [1, 1, 2]
pos.loc[4,'id'] = [1, 2, 1]

print(pos)

print(pos[pos['id'] == [1, 1, 2]].index[0])


I am getting an error:

ValueError: ('Lengths must match to compare', (6,), (3,))

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