python - 如何在使用python读取CSV文件时跳过空白行

Question

这是我的代码，我可以打印每一行，但是当出现空行时它会打印；因为 CSV 文件格式，所以我想在出现空行时跳过

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

如果你想跳过所有的空白行，你应该使用这个测试：' '.isspace().

由于您可能想做一些比仅将非空行打印到控制台更复杂的事情（无需为此使用 CSV 模块），因此这里有一个涉及 DictReader 的示例：

#!/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

代替

if not line:

这应该有效：

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

Answer 3

我的建议是只使用可以将文件分隔成行的 csv 阅读器。像这样，您可以检查该行是否为空，如果是则继续。

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 4

您始终可以检查逗号分隔值的数量。它似乎更有生产力和效率。

当迭代地阅读这些行时，因为这些是逗号分隔值的列表，您将获得一个列表对象。所以如果没有元素（空白链接），那么我们可以让它跳过。

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

此示例仅以数组形式打印数据，同时跳过空行：

import csv

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

for line in data:
    if line: print line

file.close()

我发现它比其他提供的示例更清楚。

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