CSV阅读器重复阅读1行

Question

I have a csv.reader reading a file, but repeatedly reading the same line.

import csv

with open('mydata.csv', 'rb') as f:
    reader = csv.reader(f)
    reader.next()
    for row in reader:
        while i < 10:
            print row
            i=i+1

The code prints the second row (as I want to skip the header) 10 times.

Answer 1

Your code is doing exactly what you told it to do... (and also, your title is misleading: the reader is reading the row only once, you are simply printing it 10 times)

reader.next() # advances to second line
for row in reader: # loops over remaining lines
    while i < 10: # loops over i
        print row # prints current row - this would be the second row in the first forloop iteration... 10 times, because you loop over i.
        i=i+1 # increments i, so the next rows, i is already >=10, your while-loop only affects the second line.

Why do you have that while loop in the first place? You could easily do something like:

   reader = csv.reader(f)
   for rownum, row in enumerate(reader):
     if rownum: #skip first line
        print row