How can I map True/False to 1/0 in a Pandas DataFrame?

Each Answer to this Q is separated by one/two green lines.

I have a column in python pandas DataFrame that has boolean True/False values, but for further calculations I need 1/0 representation. Is there a quick pandas/numpy way to do that?

A succinct way to convert a single column of boolean values to a column of integers 1 or 0:

df["somecolumn"] = df["somecolumn"].astype(int)

Just multiply your Dataframe by 1 (int)

[1]: data = pd.DataFrame([[True, False, True], [False, False, True]])
[2]: print data
          0      1     2
     0   True  False  True
     1   False False  True

[3]: print data*1
         0  1  2
     0   1  0  1
     1   0  0  1

True is 1 in Python, and likewise False is 0*:

>>> True == 1
>>> False == 0

You should be able to perform any operations you want on them by just treating them as though they were numbers, as they are numbers:

>>> issubclass(bool, int)
>>> True * 5

So to answer your question, no work necessary – you already have what you are looking for.

* Note I use is as an English word, not the Python keyword isTrue will not be the same object as any random 1.

This question specifically mentions a single column, so the currently accepted answer works. However, it doesn’t generalize to multiple columns. For those interested in a general solution, use the following:

df.replace({False: 0, True: 1}, inplace=True)

This works for a DataFrame that contains columns of many different types, regardless of how many are boolean.

You also can do this directly on Frames

In [104]: df = DataFrame(dict(A = True, B = False),index=range(3))

In [105]: df
      A      B
0  True  False
1  True  False
2  True  False

In [106]: df.dtypes
A    bool
B    bool
dtype: object

In [107]: df.astype(int)
   A  B
0  1  0
1  1  0
2  1  0

In [108]: df.astype(int).dtypes
A    int64
B    int64
dtype: object

You can use a transformation for your data frame:

df = pd.DataFrame(my_data condition)

transforming True/False in 1/0

df = df*1

Use Series.view for convert boolean to integers:

df["somecolumn"] = df["somecolumn"].view('i1')

I had to map FAKE/REAL to 0/1 but couldn’t find proper answer.

Please find below how to map column name ‘type’ which has values FAKE/REAL to 0/1
(Note: similar can be applied to any column name and values)

df.loc[df['type'] == 'FAKE', 'type'] = 0
df.loc[df['type'] == 'REAL', 'type'] = 1

This is a reproducible example based on some of the existing answers:

import pandas as pd

def bool_to_int(s: pd.Series) -> pd.Series:
    """Convert the boolean to binary representation, maintain NaN values."""
    return s.replace({True: 1, False: 0})

# generate a random dataframe
df = pd.DataFrame({"a": range(10), "b": range(10, 0, -1)}).assign(
    a_bool=lambda df: df["a"] > 5,
    b_bool=lambda df: df["b"] % 2 == 0,

# select all bool columns (or specify which cols to use)
bool_cols = [c for c, d in df.dtypes.items() if d == "bool"]

# apply the new coding to a new dataframe (or can replace the existing one)
df_new = df.assign(**{c: lambda df: df[c].pipe(bool_to_int) for c in bool_cols})

The answers/resolutions are collected from stackoverflow, are licensed under cc by-sa 2.5 , cc by-sa 3.0 and cc by-sa 4.0 .

Leave a Reply

Your email address will not be published.