使用Python迭代字符串中的每个字符 [英] Iterating each character in a string using Python
问题描述
在C ++中,我可以像这样迭代 std :: string
:
std :: string str =Hello World!;
for(int i = 0; i< str.length(); ++ i)
{
std :: cout<< str [i]<<的std :: ENDL;
}
如何在Python中迭代字符串?
正如约翰内斯指出的那样,
for c在字符串中:
#do与c
的东西
你可以迭代几乎任何东西python使用 for循环
构造,
例如, open(file.txt )
返回一个文件对象(并打开文件),迭代它迭代该文件中的行
开放(文件名)为f:
换行f:
#用行
做某事
如果这看起来很神奇,那就好了,但背后的想法非常简单。
有一个简单的迭代器协议可以应用于任何类型的对象,使 for
循环工作。
只需实现一个定义 next()
方法的迭代器,并实现 __iter __
类上的方法使其可迭代。 ( __ iter __
当然应该返回一个迭代器对象,即一个定义 next()
的对象<) / p>
In C++, I can iterate over an std::string
like this:
std::string str = "Hello World!";
for (int i = 0; i < str.length(); ++i)
{
std::cout << str[i] << std::endl;
}
How do I iterate over a string in Python?
As Johannes pointed out,
for c in "string":
#do something with c
You can iterate pretty much anything in python using the for loop
construct,
for example, open("file.txt")
returns a file object (and opens the file), iterating over it iterates over lines in that file
with open(filename) as f:
for line in f:
# do something with line
If that seems like magic, well it kinda is, but the idea behind it is really simple.
There's a simple iterator protocol that can be applied to any kind of object to make the for
loop work on it.
Simply implement an iterator that defines a next()
method, and implement an __iter__
method on a class to make it iterable. (the __iter__
of course, should return an iterator object, that is, an object that defines next()
)
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