How to delete rows from a CSV file when I just know the row number?

Question

I am a beginner and currently writing a code in python where if the CSV's length gets more than a given number, the first row will be deleted, making space for more. Is there a function that can delete rows in a CSV just by row number?

Answer 1

There is no special function for that since that can be done with a simple for loop.

Here we have an input file which is read line by line while skipping the lines with the row number contained in rownumbers_to_remove. Notice the enumerate(...) with the start=1 parameter to make the index start at 1 instead of 0. This might improve readability a bit.

lines = list()
rownumbers_to_remove= [5,6]

with open('name-of-file.csv', 'r') as read_file:
    reader = csv.reader(read_file)
    for row_number, row in enumerate(reader, start=1):
        if(row_number not in rownumbers_to_remove):
            lines.append(row)

with open('name-of-file.csv', 'w') as write_file:
    writer = csv.writer(write_file)
    writer.writerows(lines)