Vfrdtyky

I am newbie here in StackOverflow, so if made any formal mistakes with that post, correct me pls, would be appreciated!
However, coming back to main topic: I have some issues with headers while splitting big CSV file into smaller ones. General idea is to split mentioned file according to the 1 column and create smaller files with column names, for instance:

Fruit       Country       Color

apple       Poland        red

banana      Argentina     yellow

pineapple   Argentina     brown

pear        Poland        green

melon       Turkey        yellow

plum        Poland        violet

peach       Turkey        orange

grenade     Argentina     violet

Code should generate 3 different files (Poland.csv, Turkey.csv, Argentina.csv)

So far I've made the below code which is splitting CSV correctly but cannot append headers properly (they are added through each iteration). Do you have any ideas how can I deal with it?

import csv



opener = open('file.csv', 'r', encoding='utf-8')  

csvreader = csv.reader(opener, delimiter=';')        

header = next(csvreader)



def splitter(u):                                   

    for row in u:

        with open(row[1] + '.csv', 'a', encoding='utf-8', newline='') as myfile:

          writer = csv.writer(myfile, delimiter=';', quotechar='|', quoting=csv.QUOTE_MINIMAL)

          writer.writerow(header)

          writer.writerow(row)



    myfile.close()



splitter(csvreader)

Try something like this (quick and dirty but should work):

def splitter(u):    

    filenames_already_opened =      # Just keep a list of the csv's you've already created and therefore have added a header to.           

    for row in u:

        filename = row[1] + '.csv'

        with open(filename, 'a', encoding='utf-8', newline='') as myfile:

            writer = csv.writer(myfile, delimiter=';', quotechar='|', quoting=csv.QUOTE_MINIMAL)

            if filename in filenames_already_opened:  # Don't add a header if it's already got one.

                pass

            else:

                writer.writerow(header)

                filenames_already_opened.append(filename)

            writer.writerow(row)



    myfile.close()

This fixes the problem:

import csv



opener = open('file.csv', 'r', encoding='utf-8')  

csvreader = csv.reader(opener, delimiter=';')        

header = next(csvreader)



def splitter(u):

    tableNames = 

    for row in u:

        with open(row[1] + '.csv', 'a', encoding='utf-8', newline='') as myfile:

            writer = csv.writer(myfile, delimiter=';', quotechar='|', quoting=csv.QUOTE_MINIMAL)

            if not row[1] in tableNames:

                writer.writerow(header)

                tableNames.append(row[1])

            writer.writerow(row)



    myfile.close()



splitter(csvreader)