Staging
v0.5.1
v0.5.1
https://github.com/python/cpython
Tip revision: 1da43e5e916949c8e849e656d9d05fa4b9d6836c authored by Benjamin Peterson on 26 June 2009, 13:21:52 UTC
rearrange the sections of the README, so they'll hopefully be more in the order people will interested in
rearrange the sections of the README, so they'll hopefully be more in the order people will interested in
Tip revision: 1da43e5
test_unpack.py
doctests = """
Unpack tuple
>>> t = (1, 2, 3)
>>> a, b, c = t
>>> a == 1 and b == 2 and c == 3
True
Unpack list
>>> l = [4, 5, 6]
>>> a, b, c = l
>>> a == 4 and b == 5 and c == 6
True
Unpack implied tuple
>>> a, b, c = 7, 8, 9
>>> a == 7 and b == 8 and c == 9
True
Unpack string... fun!
>>> a, b, c = 'one'
>>> a == 'o' and b == 'n' and c == 'e'
True
Unpack generic sequence
>>> class Seq:
... def __getitem__(self, i):
... if i >= 0 and i < 3: return i
... raise IndexError
...
>>> a, b, c = Seq()
>>> a == 0 and b == 1 and c == 2
True
Single element unpacking, with extra syntax
>>> st = (99,)
>>> sl = [100]
>>> a, = st
>>> a
99
>>> b, = sl
>>> b
100
Now for some failures
Unpacking non-sequence
>>> a, b, c = 7
Traceback (most recent call last):
...
TypeError: 'int' object is not iterable
Unpacking tuple of wrong size
>>> a, b = t
Traceback (most recent call last):
...
ValueError: too many values to unpack
Unpacking tuple of wrong size
>>> a, b = l
Traceback (most recent call last):
...
ValueError: too many values to unpack
Unpacking sequence too short
>>> a, b, c, d = Seq()
Traceback (most recent call last):
...
ValueError: need more than 3 values to unpack
Unpacking sequence too long
>>> a, b = Seq()
Traceback (most recent call last):
...
ValueError: too many values to unpack
Unpacking a sequence where the test for too long raises a different kind of
error
>>> class BozoError(Exception):
... pass
...
>>> class BadSeq:
... def __getitem__(self, i):
... if i >= 0 and i < 3:
... return i
... elif i == 3:
... raise BozoError
... else:
... raise IndexError
...
Trigger code while not expecting an IndexError (unpack sequence too long, wrong
error)
>>> a, b, c, d, e = BadSeq()
Traceback (most recent call last):
...
test.test_unpack.BozoError
Trigger code while expecting an IndexError (unpack sequence too short, wrong
error)
>>> a, b, c = BadSeq()
Traceback (most recent call last):
...
test.test_unpack.BozoError
"""
__test__ = {'doctests' : doctests}
def test_main(verbose=False):
from test import support
from test import test_unpack
support.run_doctest(test_unpack, verbose)
if __name__ == "__main__":
test_main(verbose=True)