in one of the columns in my dataframe I have five values:
1,G,2,3,4
How to make it change the name of all "G" to 1
I tried:
df = df['col_name'].replace({'G': 1})
I also tried:
df = df['col_name'].replace('G',1)
"G" is in fact 1 (I do not know why there is a mixed naming)
Edit:
works correctly with:
df['col_name'] = df['col_name'].replace({'G': 1})
If I am understanding your question correctly, you are trying to change the values in a column and not the column name itself.
Given you have mixed data type there, I assume that column is of type object and thus the number is read as string.
df['col_name'] = df['col_name'].str.replace('G', '1')
df['col_name'].replace({'G': 1}) won't work. Nothing magical about df['col_name'].str.replace('G', '1')) is any better. It's the assignment back to the dataframe that is messed up.
You could try the following line
df.replace('G', 1, inplace=True)
use numpy
import numpy as np
df['a'] = np.where((df.a =='G'), 1, df.a)
You can try this, lets say your data is like :
ab=pd.DataFrame({'a':[1,2,3,'G',5]})
And you will replace it as :
ab1=ab.replace('G',4)
df['col_name'].replace({'G': 1})is the right (a right) thing to do. You just need to assign it back to the dataframe appropriately.df['col_name'] = df['col_name'].replace({'G': 1})ORdf.update(df['col_name'].replace({'G': 1}))ORdf = df.assign(col_name=df['col_name'].replace({'G': 1}))