Python code coverage for Lib/test/test_genexps.py

#	count	content
1	n/a	doctests = """
2	n/a
3	n/a	Test simple loop with conditional
4	n/a
5	n/a	>>> sum(i*i for i in range(100) if i&1 == 1)
6	n/a	166650
7	n/a
8	n/a	Test simple nesting
9	n/a
10	n/a	>>> list((i,j) for i in range(3) for j in range(4) )
11	n/a	[(0, 0), (0, 1), (0, 2), (0, 3), (1, 0), (1, 1), (1, 2), (1, 3), (2, 0), (2, 1), (2, 2), (2, 3)]
12	n/a
13	n/a	Test nesting with the inner expression dependent on the outer
14	n/a
15	n/a	>>> list((i,j) for i in range(4) for j in range(i) )
16	n/a	[(1, 0), (2, 0), (2, 1), (3, 0), (3, 1), (3, 2)]
17	n/a
18	n/a	Make sure the induction variable is not exposed
19	n/a
20	n/a	>>> i = 20
21	n/a	>>> sum(i*i for i in range(100))
22	n/a	328350
23	n/a	>>> i
24	n/a	20
25	n/a
26	n/a	Test first class
27	n/a
28	n/a	>>> g = (i*i for i in range(4))
29	n/a	>>> type(g)
30	n/a	<class 'generator'>
31	n/a	>>> list(g)
32	n/a	[0, 1, 4, 9]
33	n/a
34	n/a	Test direct calls to next()
35	n/a
36	n/a	>>> g = (i*i for i in range(3))
37	n/a	>>> next(g)
38	n/a	0
39	n/a	>>> next(g)
40	n/a	1
41	n/a	>>> next(g)
42	n/a	4
43	n/a	>>> next(g)
44	n/a	Traceback (most recent call last):
45	n/a	File "<pyshell#21>", line 1, in -toplevel-
46	n/a	next(g)
47	n/a	StopIteration
48	n/a
49	n/a	Does it stay stopped?
50	n/a
51	n/a	>>> next(g)
52	n/a	Traceback (most recent call last):
53	n/a	File "<pyshell#21>", line 1, in -toplevel-
54	n/a	next(g)
55	n/a	StopIteration
56	n/a	>>> list(g)
57	n/a	[]
58	n/a
59	n/a	Test running gen when defining function is out of scope
60	n/a
61	n/a	>>> def f(n):
62	n/a	... return (i*i for i in range(n))
63	n/a	>>> list(f(10))
64	n/a	[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]
65	n/a
66	n/a	>>> def f(n):
67	n/a	... return ((i,j) for i in range(3) for j in range(n))
68	n/a	>>> list(f(4))
69	n/a	[(0, 0), (0, 1), (0, 2), (0, 3), (1, 0), (1, 1), (1, 2), (1, 3), (2, 0), (2, 1), (2, 2), (2, 3)]
70	n/a	>>> def f(n):
71	n/a	... return ((i,j) for i in range(3) for j in range(4) if j in range(n))
72	n/a	>>> list(f(4))
73	n/a	[(0, 0), (0, 1), (0, 2), (0, 3), (1, 0), (1, 1), (1, 2), (1, 3), (2, 0), (2, 1), (2, 2), (2, 3)]
74	n/a	>>> list(f(2))
75	n/a	[(0, 0), (0, 1), (1, 0), (1, 1), (2, 0), (2, 1)]
76	n/a
77	n/a	Verify that parenthesis are required in a statement
78	n/a
79	n/a	>>> def f(n):
80	n/a	... return i*i for i in range(n)
81	n/a	Traceback (most recent call last):
82	n/a	...
83	n/a	SyntaxError: invalid syntax
84	n/a
85	n/a	Verify that parenthesis are required when used as a keyword argument value
86	n/a
87	n/a	>>> dict(a = i for i in range(10))
88	n/a	Traceback (most recent call last):
89	n/a	...
90	n/a	SyntaxError: invalid syntax
91	n/a
92	n/a	Verify that parenthesis are required when used as a keyword argument value
93	n/a
94	n/a	>>> dict(a = (i for i in range(10))) #doctest: +ELLIPSIS
95	n/a	{'a': <generator object <genexpr> at ...>}
96	n/a
97	n/a	Verify early binding for the outermost for-expression
98	n/a
99	n/a	>>> x=10
100	n/a	>>> g = (i*i for i in range(x))
101	n/a	>>> x = 5
102	n/a	>>> list(g)
103	n/a	[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]
104	n/a
105	n/a	Verify that the outermost for-expression makes an immediate check
106	n/a	for iterability
107	n/a
108	n/a	>>> (i for i in 6)
109	n/a	Traceback (most recent call last):
110	n/a	File "<pyshell#4>", line 1, in -toplevel-
111	n/a	(i for i in 6)
112	n/a	TypeError: 'int' object is not iterable
113	n/a
114	n/a	Verify late binding for the outermost if-expression
115	n/a
116	n/a	>>> include = (2,4,6,8)
117	n/a	>>> g = (i*i for i in range(10) if i in include)
118	n/a	>>> include = (1,3,5,7,9)
119	n/a	>>> list(g)
120	n/a	[1, 9, 25, 49, 81]
121	n/a
122	n/a	Verify late binding for the innermost for-expression
123	n/a
124	n/a	>>> g = ((i,j) for i in range(3) for j in range(x))
125	n/a	>>> x = 4
126	n/a	>>> list(g)
127	n/a	[(0, 0), (0, 1), (0, 2), (0, 3), (1, 0), (1, 1), (1, 2), (1, 3), (2, 0), (2, 1), (2, 2), (2, 3)]
128	n/a
129	n/a	Verify re-use of tuples (a side benefit of using genexps over listcomps)
130	n/a
131	n/a	>>> tupleids = list(map(id, ((i,i) for i in range(10))))
132	n/a	>>> int(max(tupleids) - min(tupleids))
133	n/a	0
134	n/a
135	n/a	Verify that syntax error's are raised for genexps used as lvalues
136	n/a
137	n/a	>>> (y for y in (1,2)) = 10
138	n/a	Traceback (most recent call last):
139	n/a	...
140	n/a	SyntaxError: can't assign to generator expression
141	n/a
142	n/a	>>> (y for y in (1,2)) += 10
143	n/a	Traceback (most recent call last):
144	n/a	...
145	n/a	SyntaxError: can't assign to generator expression
146	n/a
147	n/a
148	n/a	########### Tests borrowed from or inspired by test_generators.py ############
149	n/a
150	n/a	Make a generator that acts like range()
151	n/a
152	n/a	>>> yrange = lambda n: (i for i in range(n))
153	n/a	>>> list(yrange(10))
154	n/a	[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
155	n/a
156	n/a	Generators always return to the most recent caller:
157	n/a
158	n/a	>>> def creator():
159	n/a	... r = yrange(5)
160	n/a	... print("creator", next(r))
161	n/a	... return r
162	n/a	>>> def caller():
163	n/a	... r = creator()
164	n/a	... for i in r:
165	n/a	... print("caller", i)
166	n/a	>>> caller()
167	n/a	creator 0
168	n/a	caller 1
169	n/a	caller 2
170	n/a	caller 3
171	n/a	caller 4
172	n/a
173	n/a	Generators can call other generators:
174	n/a
175	n/a	>>> def zrange(n):
176	n/a	... for i in yrange(n):
177	n/a	... yield i
178	n/a	>>> list(zrange(5))
179	n/a	[0, 1, 2, 3, 4]
180	n/a
181	n/a
182	n/a	Verify that a gen exp cannot be resumed while it is actively running:
183	n/a
184	n/a	>>> g = (next(me) for i in range(10))
185	n/a	>>> me = g
186	n/a	>>> next(me)
187	n/a	Traceback (most recent call last):
188	n/a	File "<pyshell#30>", line 1, in -toplevel-
189	n/a	next(me)
190	n/a	File "<pyshell#28>", line 1, in <generator expression>
191	n/a	g = (next(me) for i in range(10))
192	n/a	ValueError: generator already executing
193	n/a
194	n/a	Verify exception propagation
195	n/a
196	n/a	>>> g = (10 // i for i in (5, 0, 2))
197	n/a	>>> next(g)
198	n/a	2
199	n/a	>>> next(g)
200	n/a	Traceback (most recent call last):
201	n/a	File "<pyshell#37>", line 1, in -toplevel-
202	n/a	next(g)
203	n/a	File "<pyshell#35>", line 1, in <generator expression>
204	n/a	g = (10 // i for i in (5, 0, 2))
205	n/a	ZeroDivisionError: integer division or modulo by zero
206	n/a	>>> next(g)
207	n/a	Traceback (most recent call last):
208	n/a	File "<pyshell#38>", line 1, in -toplevel-
209	n/a	next(g)
210	n/a	StopIteration
211	n/a
212	n/a	Make sure that None is a valid return value
213	n/a
214	n/a	>>> list(None for i in range(10))
215	n/a	[None, None, None, None, None, None, None, None, None, None]
216	n/a
217	n/a	Check that generator attributes are present
218	n/a
219	n/a	>>> g = (i*i for i in range(3))
220	n/a	>>> expected = set(['gi_frame', 'gi_running'])
221	n/a	>>> set(attr for attr in dir(g) if not attr.startswith('__')) >= expected
222	n/a	True
223	n/a
224	n/a	>>> from test.support import HAVE_DOCSTRINGS
225	n/a	>>> print(g.__next__.__doc__ if HAVE_DOCSTRINGS else 'Implement next(self).')
226	n/a	Implement next(self).
227	n/a	>>> import types
228	n/a	>>> isinstance(g, types.GeneratorType)
229	n/a	True
230	n/a
231	n/a	Check the __iter__ slot is defined to return self
232	n/a
233	n/a	>>> iter(g) is g
234	n/a	True
235	n/a
236	n/a	Verify that the running flag is set properly
237	n/a
238	n/a	>>> g = (me.gi_running for i in (0,1))
239	n/a	>>> me = g
240	n/a	>>> me.gi_running
241	n/a	0
242	n/a	>>> next(me)
243	n/a	1
244	n/a	>>> me.gi_running
245	n/a	0
246	n/a
247	n/a	Verify that genexps are weakly referencable
248	n/a
249	n/a	>>> import weakref
250	n/a	>>> g = (i*i for i in range(4))
251	n/a	>>> wr = weakref.ref(g)
252	n/a	>>> wr() is g
253	n/a	True
254	n/a	>>> p = weakref.proxy(g)
255	n/a	>>> list(p)
256	n/a	[0, 1, 4, 9]
257	n/a
258	n/a
259	n/a	"""
260	n/a
261	n/a	import sys
262	n/a
263	n/a	# Trace function can throw off the tuple reuse test.
264	n/a	if hasattr(sys, 'gettrace') and sys.gettrace():
265	n/a	__test__ = {}
266	n/a	else:
267	n/a	__test__ = {'doctests' : doctests}
268	n/a
269	n/a	def test_main(verbose=None):
270	n/a	from test import support
271	n/a	from test import test_genexps
272	n/a	support.run_doctest(test_genexps, verbose)
273	n/a
274	n/a	# verify reference counting
275	n/a	if verbose and hasattr(sys, "gettotalrefcount"):
276	n/a	import gc
277	n/a	counts = [None] * 5
278	n/a	for i in range(len(counts)):
279	n/a	support.run_doctest(test_genexps, verbose)
280	n/a	gc.collect()
281	n/a	counts[i] = sys.gettotalrefcount()
282	n/a	print(counts)
283	n/a
284	n/a	if __name__ == "__main__":
285	n/a	test_main(verbose=True)