Why does python [printf r """] return the string "..." and can't exit

Question

Why does print r""" return the string ... and doesn't exit?

When I press Enter, the console displays a new row preceded by the string ...

Answer 1

Because the three quotes are seen as the beginning of a triple-quoted string. It is waiting for you to type another set of triple quotes.

>>> print r"""
... blah
... """

blah

>>> 

For more information see:

• How does Python's triple-quote string work?
• https://docs.python.org/2.7/tutorial/introduction.html#strings; search for """

(The second link is to 2.7 docs since your example used python 2.x syntax).

A direct quote from the python documentation:

String literals can span multiple lines. One way is using triple-quotes: """...""" or '''...'''. End of lines are automatically included in the string, but it’s possible to prevent this by adding a \ at the end of the line.

Answer 2

print r""" starts a multi-line string.

Because the string hasn't been terminated with another """ the interpreter keeps printing ..., waiting for you to type the next line or match the opening quotes with a closing one. So, if you type """ again the standard interpreter prompt >>> will reappear or resume.

Python 3 implementation:

>>> print("""
...   
... abc
... 
... ggg
... 
... """)


abc

ggg


>>> 

Python 2.7 implementation:

>>> print r"""
... blah
... black sheep
... """

black sheep
blah