What does += mean when used together in python?

For variable types, we can modify the variables in situ, which means that its storage space is readable and writable, such as list; for immutable types, its storage space is It is read-only and cannot be modified. If you need to perform certain operations on the immutable type to get new results, you need to create a new storage space to store the new results.

For variable types: = represents the append operation, that is, the in-place operation, which appends the content of another object to the object in place.

For immutable types: = represents a connection or sum operation, and the result of the operation will produce a new object.

>>> l = [1, 2, 3, 4, 5]
>>> id(l)
43142024
>>> l += [0]*5
>>> l[1, 2, 3, 4, 5, 0, 0, 0, 0, 0]
>>> id(l)
43142024

When using =, there is one before and after "l".

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>>> t = (1, 2, 3, 4, 5)
>>> id(t)
45438232
>>> t += (0,)*5
>>> t(1, 2, 3, 4, 5, 0, 0, 0, 0, 0)
>>> id(t)
45674568

When we replace the list with a tuple, the result changes again.

>>>s = "hello"
>>> id(s)
45794056
>>>s += "world"
>>> s'helloworld'
>>> id(s)
45495920

The result is like a tuple, "s" is reassigned after using = to concatenate a string, and is no longer the previous variable. Reflected in the memory, "s" has been opened up an additional storage space to store the value.

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