python入门问题 IndexError: list index out of range，求大神帮助，谢谢先

发布网友发布时间：2022-06-07 16:54

共2个回答

热心网友时间：2023-10-22 11:03

f = open('input.txt', 'r')
a = 0
nr_of_lines = sum(1 for line in f)
for a in range(nr_of_lines):
    if a % 2 == 1:
        b = f.readlines()[a]
        print b
    a = a + 1
f.close()

写的些什么。。。简直是c风格的python。。。。

a = 0 不要写。。。

f = open('input.txt')
for i,line in enumerate(f):
if (i + 1) % 2 == 0:
print line
f.close()

热心网友时间：2023-10-22 11:03

# encoding: utf-8
'''
Created on 2015年5月7日

@author: 传庆
'''
'''
f = open('input.txt', 'r')
a = 0
# 执行完下边的代码之后文件自动关闭了，导致f.readlines()读出的列表是空的，
# 你可以自行打印其内容进行查看，再说a % 2 == 1取的是奇数行不是偶数.
nr_of_lines = sum(1 for line in f)
print f.readlines()
print nr_of_lines
for a in range(nr_of_lines):
    if a % 2 == 1:

        b = f.readlines()[a]
        print b
    # for cycle do inc auto.
    #a = a + 1
f.close()
'''
# you can code like below
flag = False
with open('input.txt', 'r') as f:
    for line in f:
        if flag:
            print line
            flag = False
        else:
            flag = True