Create a new variable for every row in dataframe column

Question

I'm trying to create a series of variables based on an existing df column. Example :

import pandas as pd

dates = {'expiries': ['10','11','13','14']}
expiries = pd.DataFrame(dates)
expiries

I then want to create a new variable (var1 through var4) giving it the value from each row. I know I can get it by going:

var1 = expiries['expiries'].iloc[0]
var2 = expiries['expiries'].iloc[1]
var3 = expiries['expiries'].iloc[2]
var4 = expiries['expiries'].iloc[3]

but in reality my df is a variable length and I need a variable per row not a pre determined (hardcoded) number of variables.

The question is why? If you don't know the number of variables, how do you type them? Are you looking into some sort of for loop? — Quang Hoang
– Quang Hoang, Commented Mar 19, 2021 at 14:33
you can store in a dict : expiries['expiries'].to_dict() and refer the keys later if really required, since creating variables from a loop isnt a great idea. ref: stackoverflow.com/questions/1373164/… — anky
– anky, Commented Mar 19, 2021 at 14:43
I'm using the variables to create columns in a new df. I then reference that df with some visualisations. An initial product selection determines the number of expiries. Sometimes 15 sometimes 20. If I preset the variables to 20, when my product only has 15 the visualisations dont run as they are missing columns. Appreciate the advice that its anti code logic. — breaker7
– breaker7, Commented Mar 19, 2021 at 14:52

Artyom Akselrod · Accepted Answer · 2021-03-19 14:41:43Z

1

store them in the dict:

var_dict = {}
for i in range(expires.shape[0]):
    var_dict['var' + str(i+1)] = expiries['expiries'].iloc[i]

it is against coding logic that you have unknown number of variables

answered Mar 19, 2021 at 14:41

Artyom Akselrod

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Comments

Miguel Trejo · Accepted Answer · 2021-03-19 14:43:27Z

1

you could use exec

for row in expiries.itertuples():
    idx, value = row
    exec(f'var{idx+1} = {value}')

print(var1, var2, var3, var4)
>>>
10 11 13 14

answered Mar 19, 2021 at 14:43

Miguel Trejo

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