如何打印到 Python 中的字符串

Question

Lisp type languages usually provide an abstraction which allows you to open a string as a file, and then print to it using any function which can normally print to a file. When you close the string you can recuperate the string that was printed.

Does something like this exist for python?

It probably would like something like this:

f = open_string_as_output()
f.write("hello")
if some_condition:
   f.write(" ")
g(f) # allow g to write to the sting if desired
f.close()
str = f.get_string()

Answer 1

There is a class called StringIO , which does what you described.

import io
string_out = io.StringIO()
string_out.write('Foo')
if some_condition:
    string_out.write('Bar')
string_out.getvalue()  # Could be 'Foo' or 'FooBar'