I have feature in a dataframe that stores the class information of students like:
Student_ID CLass
S1 5
S2 7
S3 6
How can I prefix characters like C_ before the Class for every student?
-
2Please add what you've tried already, how you currently store the information in the dataframe.StrangeSorcerer– StrangeSorcerer2021-06-29 18:24:12 +00:00Commented Jun 29, 2021 at 18:24
Add a comment
|
3 Answers
From your question, I understood that you want to add prefix C_ to all values of class column.
If that is the case (your prefix is constant C_) , you can do something like
df['CLass'] = 'C_' + df['CLass'].astype(str)
Comments
you can do it using the apply method of pandas dataframes like this:
import pandas as pd
df = pd.DataFrame([5, 6, 7], index = ["S1", "S2", "S3"], columns = ["Class"])
df["Class"].apply(lambda x: "C_" + str(x))
Output:
S1 C_5
S2 C_6
S3 C_7
Name: Class, dtype: object
Comments
It sounds like you're looking for pd.Series.apply. Typically, it can be faster to use the special string methods for Series of strings, but I can't think of an easy way to leverage those for prepending.
>>> df = pd.DataFrame({"Student_ID": ["S1", "S2", "S3"], "Class":[5,7,6]})
>>> df
Student_ID Class
0 S1 5
1 S2 7
2 S3 6
>>> df['Class'] = df['Class'].astype(str)
>>> df['Class'] = df['Class'].apply(lambda n: 'C_' + n)
>>> df
Student_ID Class
0 S1 C_5
1 S2 C_7
2 S3 C_6
