A simple maths operation on a CSV column using python [closed]-CodePudding

So I have this CSV file that I need to plug into an API, but one of the columns is in Dollars, and I want to convert it to cents by multiplying by a 100

Here's the file

tripId,scooterId,userId,totalDuration,pickUpTime,dropOffTime,userLocationAtBooking.0,userLocationAtBooking.1,userLocationAtDropOff.0,userLocationAtDropOff.1,totalFare
18721,927,38579,45,2021-08-22 03:00:49,2021-08-22 03:45:39,24.76412,46.6493,24.76409833,46.64934,9.58
18722,434,38563,45,2021-08-22 03:01:16,2021-08-22 03:45:39,24.76412,46.64933333,24.76407,46.64933333,13.53
18723,876,38554,33,2021-08-22 03:05:57,2021-08-22 03:38:55,24.71392833,46.660645,24.7097,46.66272,0.67
18724,476,32291,65,2021-08-22 03:14:37,2021-08-22 04:18:56,24.77137833,46.64568667,24.7722,46.64523167,32.35

I only need to do the maths operation on the last column, "totalFare"

I'm still new to python, so any help would be highly appreciated.

CodePudding user response：

In case it was still unclear on how to perform the task here's an implementation using basic Python

with open('file.csv', 'r') as in_file, open('result.csv', 'w') as out_file: # Open input and output files
    out_file.write(next(in_file))                # Reads header from input file and writes to output file
    for line in in_file:                         # For each line in file (we are past header line)
        line = line.rstrip().split(',')          # Create list from comma separated string
        line[-1] = f'{100*float(line[-1]):.0f}'  # Convert last item in list to float and multiply by 100
                                                 # and convert foat to stringto 0 decimal places
            
        #line[-1] = '{:.0f}'.format(100*float(line[-1])) # Alternative to above line that doesn't use
                                                         # f-string (i.e. can use in earlier versions of Python)  
        
        out_file.write(','.join(line)   '\n')    # Output updated list as comma separated string

Output (using example input)

tripId,scooterId,userId,totalDuration,pickUpTime,dropOffTime,userLocationAtBooking.0,userLocationAtBooking.1,userLocationAtDropOff.0,userLocationAtDropOff.1,totalFare
18721,927,38579,45,2021-08-22 03:00:49,2021-08-22 03:45:39,24.76412,46.6493,24.76409833,46.64934,958
18722,434,38563,45,2021-08-22 03:01:16,2021-08-22 03:45:39,24.76412,46.64933333,24.76407,46.64933333,1353
18723,876,38554,33,2021-08-22 03:05:57,2021-08-22 03:38:55,24.71392833,46.660645,24.7097,46.66272,67
18724,476,32291,65,2021-08-22 03:14:37,2021-08-22 04:18:56,24.77137833,46.64568667,24.7722,46.64523167,3235

Alternative using Python Pandas module (much shorter solution)

import pandas as pd

df = pd.read_csv('file.csv')               # Read CSV file into Pandas DataFrame
df['totalFare'] *= 100                     # multiply total_fare by 100
df.to_csv('result.csv', index = False)     # Write to output file as csv