Question

我有这段代码：

＆＃13;

chain = '>'
contain=''

file = raw_input('Enter your filename : ')


fileName = open(file,'r')
for line in fileName:
	if chain in line :
		pass
			
	if not(chain in line):
		contain+=line
		print contain
		

fileName.close()

＆＃13;

和这个file.txt：

Python supports multiple programming paradigms, including object-oriented, imperative and functional programming. 
It features a dynamic type system and automatic memory management.
He has a large and comprehensive standard library

我得到了＆＃34; print＆＃34;：

的结果

Python supports multiple programming paradigms, including object-oriented, imperative and functional programming. 

Python supports multiple programming paradigms, including object-oriented, imperative and functional programming. 
It features a dynamic type system and automatic memory management.

Python supports multiple programming paradigms, including object-oriented, imperative and functional programming. 
It features a dynamic type system and automatic memory management.
He has a large and comprehensive standard library

为什么我有重复项？

Answer 1

在循环的每次迭代中，时间：

if not(chain in line):
    contain+=line
    print(contain)

因为你连接contain中的每一行，当你打印它时，它会显示第一次迭代，第一次迭代，第二次迭代中的第一个+第二个句子，依此类推。因此重复。

用print(contain)替换print(line)将打印不重复的行。

Answer 2

第一次迭代后，您将文件的第一行添加到contain，然后打印出来。

在第二次迭代之后，您将文件的第二行添加到contain，它仍然包含第一行，然后将其打印出来。

第三次迭代也是如此。

您看到重复项，因为您多次打印contain，并且其中包含前一行。

打开文件错误，重复

2 个答案: