CODEWITHSUNDEEP
pythonpython-3.xcsv
Emre
Emre

Reputation: 33

How to pass header of csv in loop

I want to create a csv file in a loop. But when I do so, it also writes header part also. How can I write the header part only for a time?

fieldnames=['numbers']
for i in range(0,100):
    with open('numbers.csv','a',newline='') as csvfile:
        writer=csv.Dictwriter(csvfile,fieldnames=fieldnames,lineterminator='\n')
        writer.writeheader()
        writer.writerow({'numbers':i})

Upvotes: 0

Views: 222

Answers (1)

bruno desthuilliers
bruno desthuilliers

Reputation: 77912

Quite simply: move this part out of the loop (seems obvious...). You DONT want to reopen the file in each iteration anyway (opening a file - and closing it FWIW - is far from free):

fieldnames=['numbers']
with open('numbers.csv','a',newline='') as csvfile:
    writer = csv.Dictwriter(csvfile,fieldnames=fieldnames,lineterminator='\n')
    writer.writeheader()
    for i in range(100):
        writer.writerow({'numbers':i})

Upvotes: 3

Related Questions