Pandas data frame replace values in column based on condition
Question:
I have a column in data frame like this (an simplify example):
col
a
b
c
d
e
f
g
and I want to change the values like this:
col
a
b
other
other
other
other
other
I tried like this:
df = df.loc[df.col == ("a" or "b"), "col"] = "other"
but it does not work, I have an error:
AttributeError: 'str' object has no attribute 'loc'
Any advices?
Answers:
The problem with your code is, that df is changing to type string during the process.
There exists a pandas function for this usecase, named pd.where().
df = df.where(df['col'].isin(['a', 'b']),'other')
Similar result avoiding where():
df[~df['col'].isin(['a', 'b'])] = 'other'
I have a column in data frame like this (an simplify example):
col
a
b
c
d
e
f
g
and I want to change the values like this:
col
a
b
other
other
other
other
other
I tried like this:
df = df.loc[df.col == ("a" or "b"), "col"] = "other"
but it does not work, I have an error:
AttributeError: 'str' object has no attribute 'loc'
Any advices?
The problem with your code is, that df is changing to type string during the process.
There exists a pandas function for this usecase, named pd.where().
df = df.where(df['col'].isin(['a', 'b']),'other')
Similar result avoiding where():
df[~df['col'].isin(['a', 'b'])] = 'other'