Python：跳过没有字母/数字的所有行

Question

I couldn't find this asked anywhere, I'm kind of surprised. I'm trying to read in a huge file line-by-line using this:

with open("file.csv") as f:
    for line in f:
        splitline = line.split()

If I print(splitline) , I get many many lines with just commas, that I don't want:

[',,,,,,,']

Lines I do want look like:

['XZ02345,AAA,BBB,1.0,11.0,15.0,1.0,1.0']

I have tried all kinds of if 'XZ' in splitline: print(splitline) and if splitline[0] == "": continue type solutions, but anything I try either prints all lines or none.

Desired output is no lines that are just commas [',,,,,,,']

Answer 1

you can use regex

import re

with open("file.csv") as f:
    for line in f:
        if re.match(r'^\,*$', line) is None:
            splitline = line.split()
            print(splitline)

This tries to find string only with , , and if string has anything else, it processes the string

Answer 2

Try this:

with open("file.csv") as f:
    for line in f:
        if(re.sub('[^0-9a-zA-Z]+', '', str(line))):
            splitline = line.split()

Answer 3

you got [',,,,,,,'] because you do not have data filled in the csv row

you could print if there is actual data:

delimiter = ','
if splitline.replace(delimiter, '').strip():
    print(splitline.split())

Answer 4

If you are really just interested if there are not only commas (which is different from your question title), you can use the following:

empty = True
for char in splitline[0]: 
    if char != ',':
        empty = False
        break

if empty:
   continue

Less verbose

if not any([char != ',' for char in splitline[0]]):
    continue

If it's really just about the exact pattern you should be able to use the comment from Aran-Fey :

if splitline == [',,,,,,,']:
    continue

Answer 5

在 split() 函数下面添加条件 if splitline.replace(',','') !='': 控制打印不打印 ,,,,,,,, 行。