如何在使用python读取CSV文件时跳过空行

Question

This is my code i am able to print each line but when blank line appears it prints ; because of CSV file format, so i want to skip when blank line appears

import csv
import time

ifile = open ("C:\Users\BKA4ABT\Desktop\Test_Specification\RDBI.csv", "rb")
for line in csv.reader(ifile): 
    if not line: 
        empty_lines += 1 
        continue
    print line

Answer 1

If you want to skip all whitespace lines, you should use this test: ' '.isspace() .

Since you may want to do something more complicated than just printing the non-blank lines to the console(no need to use CSV module for that), here is an example that involves a DictReader:

#!/usr/bin/env python
# Tested with Python 2.7

# I prefer this style of importing - hides the csv module
# in case you do from this_file.py import * inside of __init__.py
import csv as _csv


# Real comments are more complicated ...
def is_comment(line):
    return line.startswith('#')


# Kind of sily wrapper
def is_whitespace(line):
    return line.isspace()


def iter_filtered(in_file, *filters):
    for line in in_file:
        if not any(fltr(line) for fltr in filters):
            yield line


# A dis-advantage of this approach is that it requires storing rows in RAM
# However, the largest CSV files I worked with were all under 100 Mb
def read_and_filter_csv(csv_path, *filters):
    with open(csv_path, 'rb') as fin:
        iter_clean_lines = iter_filtered(fin, *filters)
        reader = _csv.DictReader(iter_clean_lines, delimiter=';')
        return [row for row in reader]


# Stores all processed lines in RAM
def main_v1(csv_path):
    for row in read_and_filter_csv(csv_path, is_comment, is_whitespace):
        print(row)  # Or do something else with it


# Simpler, less refactored version, does not use with
def main_v2(csv_path):
    try:
        fin = open(csv_path, 'rb')
        reader = _csv.DictReader((line for line in fin if not
                                  line.startswith('#') and not line.isspace()),
                                  delimiter=';')
        for row in reader:
            print(row)  # Or do something else with it
    finally:
        fin.close()


if __name__ == '__main__':
    csv_path = "C:\Users\BKA4ABT\Desktop\Test_Specification\RDBI.csv"
    main_v1(csv_path)
    print('\n'*3)
    main_v2(csv_path)

Answer 2

Instead of

if not line:

This should work:

if not ''.join(line).strip():

Answer 3

You can always check for the number of comma separated values. It seems to be much more productive and efficient.

When reading the lines iteratively, as these are a list of comma separated values you would be getting a list object. So if there is no element (blank link), then we can make it skip.

        with open(filename) as csv_file:
          csv_reader = csv.reader(csv_file, delimiter=",")
          for row in csv_reader:
            if len(row) == 0:
                continue

Answer 4

my suggestion would be to just use the csv reader who can delimite the file into rows. Like this you can just check whether the row is empty and if so just continue.

import csv

with open('some.csv', 'r') as csvfile:

    # the delimiter depends on how your CSV seperates values
    csvReader = csv.reader(csvfile, delimiter = '\t')

    for row in csvReader:
        # check if row is empty
        if not (row):    
            continue

Answer 5

您可以去除前导和尾随空格，如果长度为零，则该行为空。

Answer 6

import csv

with open('userlist.csv') as f:

    reader = csv.reader(f)
    user_header = next(reader)       # Add this line if there the header is

    user_list = []                   # Create a  new user list for input
    for row in reader:
        if any(row):                 # Pick up the non-blank row of list
            print (row)              # Just for verification
            user_list.append(row)    # Compose all the rest data into the list

Answer 7

This example just prints the data in array form while skipping the empty lines:

import csv

file = open("data.csv", "r")
data = csv.reader(file)

for line in data:
    if line: print line

file.close()

I find it much clearer than the other provided examples.

Answer 8

import csv
ifile=csv.reader(open('C:\Users\BKA4ABT\Desktop\Test_Specification\RDBI.csv', 'rb'),delimiter=';')
for line in ifile:
    if set(line).pop()=='':
        pass
    else:
        for cell_value in line:
            print cell_value