Generate random number in csv file with python

Question

I am struggling with an issue regarding CSV files and Python. How would I generate a random number in a csv file row, based of a condition in that row.

Essentially, if the value in the first column is 'A' I want a random number between (1 and 5). If the value is B I want a random number between (2 and 6) and if the value is C, and random number between (3 and 7).

CSV File

Letter	Color	Random Number
A	Green
C	Red
B	Red
B	Green
C	Blue

Thanks in advance

The only thing I have found was creating a new random number dataframe. But I need to create a random number for an existing df.

Answer 1

Here is a simple way doing it without using pandas. this program modifies the third column by random number from a CSV file:

if the value in the first column is 'A' I want a random number between (1 and 5). If the value is B I want a random number between (2 and 6) and if the value is C, and random number between (3 and 7).

import csv
import random
letters_randoms = {
    'A': [1, 5],
    'B': [2, 6],
    'C': [3, 7],
}
rows = [] #result
with open('file.csv', 'r', encoding='utf-8') as file:
    reader = csv.reader(file)
    rows.append(next(reader))  # Skip the first line (header)
    for row in reader:
        letter = row[0].upper()
        row[2] = random.randint(letters_randoms[letter]
                                [0], letters_randoms[letter][1])# or just *letters_randoms[letter]
        rows.append(row)
# modify csv file
with open('file.csv', 'w', newline='', encoding='utf-8') as file:
    writer = csv.writer(file)
    writer.writerows(rows)

Result:(file.csv)

LETTER,COLOR,Random Number
A,Green,3
c,Red,5
B,Red,2
B,Green,2
c,Blue,5
A,Purple,5
B,Green,3
A,Orange,3
c,Black,4
c,Red,5