Python: What does "myvar = 1000," do?

Question

Earlier I was making some code and when I made a typo while making the variable myvar, it did not through an error or act differently. Here is the line:

myvar, var2 = 1000, 1000,

Why is there not an error?

Answer 1

With the new example, you're actually still dealing with tuples. If you print out what the right hand side is, you'll get

testVar = 1000, 1000,
print(testVar)

# result:
(1000,1000)

What is actually happening under the hood is that Python sees a tuple, then unpacks it into two values and assigns one to myvar and the other to var2. At the end of the day, the right hand side still acts as a tuple.

In fact, another way we know this to be true is if we try to unpack it but we do not provide enough variables:

myvar, = 1000, 1000,

This throws an exception:

ValueError: too many values to unpack (expected 1)

Answer 2

You are generating a tuple and unpack it at the same time into two different variables. You could check with

mytuple = 1000, 1000,

This will generate a tuple of (1000,1000) whether the comma in the end is there or not (there's no value following).
You'd generate a tuple of size 1 with

mytuple = 1000,

Now, you're effectively destructing the tuple in the next step with

myvar, var2 = 1000, 1000,

In the end you have two variables of type int.

Answer 3

You have edited your post, so now it asks a different question.

In [1]: myvar = 10, 10

In [2]: myvar
Out[2]: (10, 10)

In [3]: myvar[0]
Out[3]: 10

In [4]: myvar, myvar2 = 10, 10

In [5]: myvar
Out[5]: 10

In [6]: myvar2
Out[6]: 10

In [7]: myvar, myvar2 = [10, 100] # A list

In [8]: myvar
Out[8]: 10

In [9]: myvar2
Out[9]: 100