How to give column name dynamicaly in pandas assign

Question

I have a dataFrame with two columns

lst = [['James',15],['Michael',10]]
df1 = pd.DataFrame(lst,columns = ['name','val'])

I only want to use pandas assign function to do the bellow task

col = 'val'
df1 = df1.assign(col=lambda x: x.val+10)

Which gives me this output

      name  val  col
0    James   25   35
1  Michael   20   30

But i actually want this

      name  val
0    James   25
1  Michael   20

I want to pass the column name val in col variable

col = 'val' i just wanted to do the addition on column val. assign is taking col as a column name but i want it as a variable and pass val — Ajay Chinni
– Ajay Chinni, Commented Aug 13, 2020 at 12:52
@AjayChinni You are using [15,10] in initial df1 so expected output would be [25,20] please update question accordingly. — Dishin Goyani
– Dishin Goyani, Commented Aug 13, 2020 at 12:59
@DishinHGoyani Thanks for understanding my question and even correcting it. Perfect — Ajay Chinni
– Ajay Chinni, Commented Aug 13, 2020 at 13:05

Dishin Goyani · Accepted Answer · 2020-08-13 12:59:53Z

2

It accept *kwargs keyword argument. So you can make first dictionary and then unpack using **.

col = 'val'
df1 = df1.assign(**{col:lambda x: x.val+10})
df1
      name  val
0    James   25
1  Michael   20

answered Aug 13, 2020 at 12:53

Dishin Goyani

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