简化:
def my_in(obj, container):
for elem in container:
if bool(my_compare_equal(obj, elem)):
return True
return False
def my_compare_equal(obj, elem):
if id(obj) == id(elem):
return True
return obj.__eq__(elem)
有关更多数据,请参阅
list_contains
然后
PyObject_RichCompareBool
,
PyObject_RichCompare
,
do_richcompare
“伪执行”步骤:
c = [AA('x', np.arange(3)),
AA('x', np.arange(3)),
AA('y', np.arange(3))]
c[0] in c
# explain:
my_in(obj=c[0], container=c)
# for loop:
# 0-iteration:
# elem = c[0]
my_compare_equal(obj=c[0], elem=c[0])
# (id(c[0]) == id(c[0])) == True
# --> True
bool(True)
# True.__bool__()
# --> True
# --> True
c[1] in c
# explain:
my_in(obj=c[1], container=c)
# for loop:
# 0-iteration:
# elem = c[0]
my_compare_equal(obj=c[1], elem=c[0])
# (id(c[1]) == id(c[0])) == False
# c[1].__eq__(c[0])
# compare tuples element by element:
# 0-iteration:
my_compare_equal('x', 'x') == True
# 1-iteration:
my_compare_equal(np.arange(3), np.arange(3))
# (id(np.arange(3)) == id(np.arange(3))) == False
# np.arange(3).__eq__(np.arange(3))
# --> np.ndarray([True, True, True])
bool(np.ndarray([True, True, True]))
# np.ndarray([True, True, True]).__bool__()
raise ValueError("The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()")
c[2] in c
# explain:
my_in(obj=c[2], container=c)
# for loop:
# 0-iteration:
# elem = c[0]
my_compare_equal(obj=c[2], elem=c[0])
# (id(c[2]) == id(c[0])) == False
# c[2].__eq__(c[0])
# compare tuples element by element:
# 0-iteration:
my_compare_equal('y', 'x') == False
# --> False
# --> False
# 1-iteration:
# analogiusly as 0-iteration:
my_compare_equal(obj=c[2], elem=c[1])
# --> False
# 2-iteration:
my_compare_equal(obj=c[2], elem=c[2])
# (id(c[2]) == id(c[2])) == True
# --> True
# --> True
