Why do i get this TypeError: 'int' object is not iterable python?

Why do i get this TypeError: 'int' object is not iterable python?

为什么会出现这种类型的错误? 通常,我现在会使用 enumerate(),但我特别想在这个给定范围内迭代:

r1 = (0,0,100,100)
r2 = (20,20,40,40)
r3 = (40,40,80,80)
these_objects = []
objects.append(r1)
objects.append(r2)
objects.append(r3)
objects_clone = copy.copy(these_objects)
iterations = int(len(objects_clone))-1
print(iterations)

for this_index, this_object in range(0, iterations):
    # ...

异常:

2
Traceback (most recent call last):
  File "test/test.py", line 50, in <module>
    for this_index, this_object in range(0, iterations):
TypeError: 'int' object is not iterable

range(0, iterations) 对象生成整数,而不是元组。您要求 for 循环将每个整数解包为两个变量:

for this_index, this_object in range(0, iterations):

整数解包失败:

>>> this_index, this_object = 0
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'int' object is not iterable

您可以在一秒钟内迭代索引并提取对象:

for this_index in range(iterations):
    this_object = objects_clone[this_index]
    # ...

如果您想枚举除最后一个对象之外的所有对象,也许您想要 slice 以忽略最后一个元素:

for this_index, this_object in enumerate(objects_clone[:-1]):
    # ...

如果你想把索引和元素放在一起,你确实应该使用enumerate()。这就是它的用途。 range(),另一方面,一次给你一个对象:一个整数。而且,由于每个整数只有一个对象,您不能将每个整数解包为两个对象。这就是为什么 for i in range(num): 是一个如此常见的结构,而 for i,j in range(num): 不是。