问题
Typing string.whitespace gives you a string containing all whitespace characters defined by Python's string module:
'\t\n\x0b\x0c\r '
Both \x0b and \x0c seem to give a vertical tab.
>>> print 'first\x0bsecond'
first
second
\v gives the same effect. How are these three different? Why does the string module use \x0b or \x0c over the simpler \v?
回答1:
\v is \x0b:
>>> '\v'
'\x0b'
but the string literal representation in Python is using the \x0b notation instead.
The Python string literal representation only ever uses \n, \r and \t, everything else that is not a printable ASCII character is represented using the \xhh notation instead.
\x0c is a form feed; it forces a printer to move to the next sheet of paper. You can also express it as \f in Python:
>>> '\f'
'\x0c'
In terminals the effects of \v and \f are often the same.
来源：https://stackoverflow.com/questions/26184100/how-does-v-differ-from-x0b-or-x0c