CODEWITHSUNDEEP
pythonpandas
Dread
Dread

Reputation: 861

Change case for columns in list

How do I change the case for data frame columns that are in a list? I know how to make all columns upper case but I don't know how to only make specific columns upper case. 

d = {'name':['bob','john','sue'],'id':[545,689,143],'fte':[1,.5,.75]}
df = pd.DataFrame(d)
# list of columns I want to make upper case
cols = ['id','fte']

This doesn't do anything (no error and case isn't changed):

df[cols].rename(str.upper,axis=1,inplace=True)
df


    name    id  fte
0   bob     545     1.00
1   john    689     0.50
2   sue     143     0.75

Upvotes: 2

Views: 387

Answers (4)

DataPsycho
DataPsycho

Reputation: 988

First you can create a map:

# create map manually
col_map = {"id": "ID", "fte": "FTE"}
# or create map automatically
col_map = {item:item.upper() for item in list(df.columns)[1:]}

Then replace the columns index:

df = df.rename(columns=col_map)

Upvotes: 0

BENY
BENY

Reputation: 323276

IIUC

df.rename(columns=dict(zip(cols,list(map(str.upper,cols)))))
Out[1135]: 
   name   ID   FTE
0   bob  545  1.00
1  john  689  0.50
2   sue  143  0.75

Upvotes: 4

Prince Francis
Prince Francis

Reputation: 3097

You could also use rename as follows

import pandas as pd

d = {'name':['bob','john','sue'],'id':[545,689,143],'fte':[1,.5,.75]}
df = pd.DataFrame(d)
# list of columns I want to make upper case
cols = ['id','fte']
newColumns = {oldName: oldName.upper() for oldName in cols}
df.rename(columns=newColumns, inplace=True)
print(df)

Upvotes: 2

yatu
yatu

Reputation: 88236

It won't work the way you're trying to do it, the reason being that indices do not support mutable operations. So one thing you could do is to use a list comprehension to generate a new list of column names an reassign it to df.columns:

df.columns = [i.upper() if i in cols else i for i in df.columns]
print(df.columns)
# Index(['name', 'ID', 'FTE'], dtype='object')

Upvotes: 5

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