Insert a multiple constant value after header in csv file using python

[shantanu97]

Is it possible to insert 9 new lines of Constant Value("AA") in a CSV starting from the 2nd row? I need to insert the "AA" at the top 9 rows(after the header).

Original CSV look like this: LEID,MI_RL,TOTDEPTH, INSERTED 07JW01,51,120,2/10/2014 10:37 DD18006,40,10,20/10/2018 16:55

Final CSV should Look like this:

LEID,MI_RL,TOTDEPTH, INSERTED AA,AA,AA,AA AA,AA,AA,AA AA,AA,AA,AA AA,AA,AA,AA AA,AA,AA,AA AA,AA,AA,AA AA,AA,AA,AA AA,AA,AA,AA AA,AA,AA,AA 07JW01,51,120,2/10/2014 10:37 DD18006,40,10,20/10/2018 16:55

The other issue is that every CSV has a different number of columns? see another csv file has 5 columns.

OLEID,FROM,TO,ZON,PROS 07WJ05,0,125,ARCN,ABC DDH006,891.68,7854,BASE,DEF DD1,25687,15987,GOOD,NEM

My code:

import os def prepend_multiple_lines(file_name, list_of_lines): # define name of temporary dummy file dummy_file = file_name + '.csv' # open given original file in read mode and dummy file in write mode with open(file_name, 'r') as read_obj, open(dummy_file, 'w') as write_obj: # Iterate over the given list of strings and write them to dummy file as lines for line in list_of_lines: write_obj.write(line + '\n') # Read lines from original file one by one and append them to the dummy file for line in read_obj: write_obj.write(line) # remove original file os.remove(file_name) # Rename dummy file as the original file os.rename(dummy_file, file_name) def main(): print('*** Insert multiple lines from the second position of a file ***') list_of_lines = ['AA','AA','AA','AA','AA','AA','AA','AA','AA'] #add 9 AA constant value prepend_multiple_lines("DB_1.csv", list_of_lines) if __name__ == '__main__': main()

The code is not working??? Can anyone help what is wrong with that code.

[Pedroski55]

Makes a change from doing sudokus!

Maybe like this, very simple:

def myApp(): import csv import glob # maybe use linecache? #import linecache path2csv = '/home/pedro/myPython/csv/' files = glob.glob(path2csv + '*.csv') for f in files: print('The csv files are', f) myfile = input('copy and paste the file you want to modify ... ') with open(myfile) as mf: mylist = mf.readlines() mystring = input('What do you want to put in the columns? Enter a string like AA ... ') # could get the number of columns automatically by splitting mylist[0] and get the len(mylist[0].split(',')) num_cols = input('How many columns of the string do you want? ') num_rows = input('How many rows of columns with the string do you want? ') # make 1 row a_row = '' for i in range(int(num_cols)): if not i == int(num_cols) -1: a_row = a_row + mystring + ',' else: a_row = a_row + mystring + '\n' insert_string = int(num_rows) * a_row headers = mylist[0] new_start = headers + insert_string # get a slice of mylist without the headers new_list = mylist[1:] new_list_string = ''.join(new_list) new_csv_string = new_start + new_list_string with open(path2csv + 'modified_csv.csv', 'w') as nf: nf.write(new_csv_string) # check the result with open(path2csv + 'modified_csv.csv') as infile: result = csv.reader(infile) for line in result: print(line)