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()
)