Interpret columns of zeros and ones as binary and store as an integer column

Question

I have a dataframe of zeros and ones. I want to treat each column as if its values were a binary representation of an integer. What is easiest way to make this conversion?

Answer 1

You can create a string from the column values and then use int(binary_string, base=2) to convert to integer:

df.apply(lambda col: int(''.join(str(v) for v in col), 2))
Out[6]: 
0    12
1     6
2    11
dtype: int64

Not sure about efficiency, multiplying by the relevant powers of 2 then summing probably takes better advantage of fast numpy operations, this is probably more convenient though.