Python reading csv files and then writing them to another

Question

I need to use if else statements to grade a csv file and then write them to another csv file.

with open('arvud.csv' , 'r') as arvud:
    for Hinne in arvud:
        print(Hinne)
        x= int(Hinne)
        if x > 90:
            print ("Hinne 5")
        elif 80 < x < 91:
            print ("Hinne 4")
        elif 70 < x < 81:
            print ("Hinne 3")
        elif 60 < x <71:
            print ("Hinne 2")
        elif 51 < x < 61:
            print ("Hinne 1")
        elif x < 50:
            print ("Hinne 0")

I have got the grading part but cant seem to find a way to write them to a csv file as two columns one for the the grade and for the score. [enter image description here][1]

Answer 1

You could change your print statements to append the grades to a list. Then write that list to a csv file. Like this:

data = []
with open('arvud.csv' , 'r') as arvud:
    for Hinne in arvud:
        print(Hinne)
        x= int(Hinne)
        if x > 90:
            data.append(5)
        elif 80 < x < 91:
            data.append(4)
        elif 70 < x < 81:
            data.append(3)
        elif 60 < x <71:
            data.append(2)
        elif 51 < x < 61:
            data.append(1)
        elif x < 50:
            data.append(0)

You should get a resulting list that looks something like [2, 4, 0...]

Then just write that list to a csv file like so:

import csv
with open('csv_file_name.csv', 'a+', newline='') as file:
    writer = csv.writer(file)
    writer.writerows(data)

You could also save time by appending each grade to the csv file each iteration but I wanted to provide an answer that used your code to help you understand what steps to take next based on what you've done so far.

Answer 2

You could redirect your current print statements to a file.

• stdout is where print writes too (ie normally your terminal)
• we can change this temporary to be a file

Code

 import sys

old_stdout = sys.stdout  # cache current setting of stdout

with open('arvud.csv' , 'r') as arvud, \
     open('out_arvud.csv', 'w') as sys.stdout:  # set stdout to file
    for Hinne in arvud:
        print(Hinne)
        x= int(Hinne)
        if x > 90:
            print ("Hinne 5")
        elif 80 < x < 91:
            print ("Hinne 4")
        elif 70 < x < 81:
            print ("Hinne 3")
        elif 60 < x <71:
            print ("Hinne 2")
        elif 51 < x < 61:
            print ("Hinne 1")
        elif x < 50:
            print ("Hinne 0")
            
sys.stdout = old_stdout # reset stdout initial setting