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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_listcomps.py
doctests = """
########### Tests borrowed from or inspired by test_genexps.py ############
Test simple loop with conditional
>>> sum([i*i for i in range(100) if i&1 == 1])
166650
Test simple nesting
>>> [(i,j) for i in range(3) for j in range(4)]
[(0, 0), (0, 1), (0, 2), (0, 3), (1, 0), (1, 1), (1, 2), (1, 3), (2, 0), (2, 1), (2, 2), (2, 3)]
Test nesting with the inner expression dependent on the outer
>>> [(i,j) for i in range(4) for j in range(i)]
[(1, 0), (2, 0), (2, 1), (3, 0), (3, 1), (3, 2)]
Make sure the induction variable is not exposed
>>> i = 20
>>> sum([i*i for i in range(100)])
328350
>>> i
20
Verify that syntax error's are raised for listcomps used as lvalues
>>> [y for y in (1,2)] = 10 # doctest: +IGNORE_EXCEPTION_DETAIL
Traceback (most recent call last):
...
SyntaxError: ...
>>> [y for y in (1,2)] += 10 # doctest: +IGNORE_EXCEPTION_DETAIL
Traceback (most recent call last):
...
SyntaxError: ...
########### Tests borrowed from or inspired by test_generators.py ############
Make a nested list comprehension that acts like range()
>>> def frange(n):
... return [i for i in range(n)]
>>> frange(10)
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
Same again, only as a lambda expression instead of a function definition
>>> lrange = lambda n: [i for i in range(n)]
>>> lrange(10)
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
Generators can call other generators:
>>> def grange(n):
... for x in [i for i in range(n)]:
... yield x
>>> list(grange(5))
[0, 1, 2, 3, 4]
Make sure that None is a valid return value
>>> [None for i in range(10)]
[None, None, None, None, None, None, None, None, None, None]
########### Tests for various scoping corner cases ############
Return lambdas that use the iteration variable as a default argument
>>> items = [(lambda i=i: i) for i in range(5)]
>>> [x() for x in items]
[0, 1, 2, 3, 4]
Same again, only this time as a closure variable
>>> items = [(lambda: i) for i in range(5)]
>>> [x() for x in items]
[4, 4, 4, 4, 4]
Another way to test that the iteration variable is local to the list comp
>>> items = [(lambda: i) for i in range(5)]
>>> i = 20
>>> [x() for x in items]
[4, 4, 4, 4, 4]
And confirm that a closure can jump over the list comp scope
>>> items = [(lambda: y) for i in range(5)]
>>> y = 2
>>> [x() for x in items]
[2, 2, 2, 2, 2]
We also repeat each of the above scoping tests inside a function
>>> def test_func():
... items = [(lambda i=i: i) for i in range(5)]
... return [x() for x in items]
>>> test_func()
[0, 1, 2, 3, 4]
>>> def test_func():
... items = [(lambda: i) for i in range(5)]
... return [x() for x in items]
>>> test_func()
[4, 4, 4, 4, 4]
>>> def test_func():
... items = [(lambda: i) for i in range(5)]
... i = 20
... return [x() for x in items]
>>> test_func()
[4, 4, 4, 4, 4]
>>> def test_func():
... items = [(lambda: y) for i in range(5)]
... y = 2
... return [x() for x in items]
>>> test_func()
[2, 2, 2, 2, 2]
"""
__test__ = {'doctests' : doctests}
def test_main(verbose=None):
import sys
from test import support
from test import test_listcomps
support.run_doctest(test_listcomps, verbose)
# verify reference counting
if verbose and hasattr(sys, "gettotalrefcount"):
import gc
counts = [None] * 5
for i in range(len(counts)):
support.run_doctest(test_genexps, verbose)
gc.collect()
counts[i] = sys.gettotalrefcount()
print(counts)
if __name__ == "__main__":
test_main(verbose=True)
doctests = """
########### Tests borrowed from or inspired by test_genexps.py ############
Test simple loop with conditional
>>> sum([i*i for i in range(100) if i&1 == 1])
166650
Test simple nesting
>>> [(i,j) for i in range(3) for j in range(4)]
[(0, 0), (0, 1), (0, 2), (0, 3), (1, 0), (1, 1), (1, 2), (1, 3), (2, 0), (2, 1), (2, 2), (2, 3)]
Test nesting with the inner expression dependent on the outer
>>> [(i,j) for i in range(4) for j in range(i)]
[(1, 0), (2, 0), (2, 1), (3, 0), (3, 1), (3, 2)]
Make sure the induction variable is not exposed
>>> i = 20
>>> sum([i*i for i in range(100)])
328350
>>> i
20
Verify that syntax error's are raised for listcomps used as lvalues
>>> [y for y in (1,2)] = 10 # doctest: +IGNORE_EXCEPTION_DETAIL
Traceback (most recent call last):
...
SyntaxError: ...
>>> [y for y in (1,2)] += 10 # doctest: +IGNORE_EXCEPTION_DETAIL
Traceback (most recent call last):
...
SyntaxError: ...
########### Tests borrowed from or inspired by test_generators.py ############
Make a nested list comprehension that acts like range()
>>> def frange(n):
... return [i for i in range(n)]
>>> frange(10)
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
Same again, only as a lambda expression instead of a function definition
>>> lrange = lambda n: [i for i in range(n)]
>>> lrange(10)
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
Generators can call other generators:
>>> def grange(n):
... for x in [i for i in range(n)]:
... yield x
>>> list(grange(5))
[0, 1, 2, 3, 4]
Make sure that None is a valid return value
>>> [None for i in range(10)]
[None, None, None, None, None, None, None, None, None, None]
########### Tests for various scoping corner cases ############
Return lambdas that use the iteration variable as a default argument
>>> items = [(lambda i=i: i) for i in range(5)]
>>> [x() for x in items]
[0, 1, 2, 3, 4]
Same again, only this time as a closure variable
>>> items = [(lambda: i) for i in range(5)]
>>> [x() for x in items]
[4, 4, 4, 4, 4]
Another way to test that the iteration variable is local to the list comp
>>> items = [(lambda: i) for i in range(5)]
>>> i = 20
>>> [x() for x in items]
[4, 4, 4, 4, 4]
And confirm that a closure can jump over the list comp scope
>>> items = [(lambda: y) for i in range(5)]
>>> y = 2
>>> [x() for x in items]
[2, 2, 2, 2, 2]
We also repeat each of the above scoping tests inside a function
>>> def test_func():
... items = [(lambda i=i: i) for i in range(5)]
... return [x() for x in items]
>>> test_func()
[0, 1, 2, 3, 4]
>>> def test_func():
... items = [(lambda: i) for i in range(5)]
... return [x() for x in items]
>>> test_func()
[4, 4, 4, 4, 4]
>>> def test_func():
... items = [(lambda: i) for i in range(5)]
... i = 20
... return [x() for x in items]
>>> test_func()
[4, 4, 4, 4, 4]
>>> def test_func():
... items = [(lambda: y) for i in range(5)]
... y = 2
... return [x() for x in items]
>>> test_func()
[2, 2, 2, 2, 2]
"""
__test__ = {'doctests' : doctests}
def test_main(verbose=None):
import sys
from test import support
from test import test_listcomps
support.run_doctest(test_listcomps, verbose)
# verify reference counting
if verbose and hasattr(sys, "gettotalrefcount"):
import gc
counts = [None] * 5
for i in range(len(counts)):
support.run_doctest(test_genexps, verbose)
gc.collect()
counts[i] = sys.gettotalrefcount()
print(counts)
if __name__ == "__main__":
test_main(verbose=True)
doctests = """
########### Tests borrowed from or inspired by test_genexps.py ############
Test simple loop with conditional
>>> sum([i*i for i in range(100) if i&1 == 1])
166650
Test simple nesting
>>> [(i,j) for i in range(3) for j in range(4)]
[(0, 0), (0, 1), (0, 2), (0, 3), (1, 0), (1, 1), (1, 2), (1, 3), (2, 0), (2, 1), (2, 2), (2, 3)]
Test nesting with the inner expression dependent on the outer
>>> [(i,j) for i in range(4) for j in range(i)]
[(1, 0), (2, 0), (2, 1), (3, 0), (3, 1), (3, 2)]
Make sure the induction variable is not exposed
>>> i = 20
>>> sum([i*i for i in range(100)])
328350
>>> i
20
Verify that syntax error's are raised for listcomps used as lvalues
>>> [y for y in (1,2)] = 10 # doctest: +IGNORE_EXCEPTION_DETAIL
Traceback (most recent call last):
...
SyntaxError: ...
>>> [y for y in (1,2)] += 10 # doctest: +IGNORE_EXCEPTION_DETAIL
Traceback (most recent call last):
...
SyntaxError: ...
########### Tests borrowed from or inspired by test_generators.py ############
Make a nested list comprehension that acts like range()
>>> def frange(n):
... return [i for i in range(n)]
>>> frange(10)
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
Same again, only as a lambda expression instead of a function definition
>>> lrange = lambda n: [i for i in range(n)]
>>> lrange(10)
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
Generators can call other generators:
>>> def grange(n):
... for x in [i for i in range(n)]:
... yield x
>>> list(grange(5))
[0, 1, 2, 3, 4]
Make sure that None is a valid return value
>>> [None for i in range(10)]
[None, None, None, None, None, None, None, None, None, None]
########### Tests for various scoping corner cases ############
Return lambdas that use the iteration variable as a default argument
>>> items = [(lambda i=i: i) for i in range(5)]
>>> [x() for x in items]
[0, 1, 2, 3, 4]
Same again, only this time as a closure variable
>>> items = [(lambda: i) for i in range(5)]
>>> [x() for x in items]
[4, 4, 4, 4, 4]
Another way to test that the iteration variable is local to the list comp
>>> items = [(lambda: i) for i in range(5)]
>>> i = 20
>>> [x() for x in items]
[4, 4, 4, 4, 4]
And confirm that a closure can jump over the list comp scope
>>> items = [(lambda: y) for i in range(5)]
>>> y = 2
>>> [x() for x in items]
[2, 2, 2, 2, 2]
We also repeat each of the above scoping tests inside a function
>>> def test_func():
... items = [(lambda i=i: i) for i in range(5)]
... return [x() for x in items]
>>> test_func()
[0, 1, 2, 3, 4]
>>> def test_func():
... items = [(lambda: i) for i in range(5)]
... return [x() for x in items]
>>> test_func()
[4, 4, 4, 4, 4]
>>> def test_func():
... items = [(lambda: i) for i in range(5)]
... i = 20
... return [x() for x in items]
>>> test_func()
[4, 4, 4, 4, 4]
>>> def test_func():
... items = [(lambda: y) for i in range(5)]
... y = 2
... return [x() for x in items]
>>> test_func()
[2, 2, 2, 2, 2]
"""
__test__ = {'doctests' : doctests}
def test_main(verbose=None):
import sys
from test import support
from test import test_listcomps
support.run_doctest(test_listcomps, verbose)
# verify reference counting
if verbose and hasattr(sys, "gettotalrefcount"):
import gc
counts = [None] * 5
for i in range(len(counts)):
support.run_doctest(test_listcomps, verbose)
gc.collect()
counts[i] = sys.gettotalrefcount()
print(counts)
if __name__ == "__main__":
test_main(verbose=True)