Edit: It seems this question is confused with list slicing and wrong code being used. Clarified the question further.
I would like to ask what do the following 2 lines of code literally mean in python.
In [51]: data = list(range(10))
In [53]: data[-1]
Background
I accidentally ran the above raw Jupyter Notebook output through a python syntax checker (pylint) and surprisingly it did not throw out a syntax error, but instead
In [53]: data[-1]
^ (bad-whitespace)
code2.py:1:0: C0111: Missing module docstring (missing-docstring)
code2.py:1:0: E0602: Undefined variable 'In' (undefined-variable)
code2.py:1:9: E0602: Undefined variable 'data' (undefined-variable)
code2.py:2:0: E0602: Undefined variable 'In' (undefined-variable)
code2.py:2:9: E0602: Undefined variable 'data' (undefined-variable)
------------------------------------------------------------------------
Your code has been rated at -115.00/10 (previous run: -90.00/10, -25.00)
So I tried understanding what those lines of code were literally doing.
And I tried plugging in the missing variables.
This Is where I got the following result that looks like a dictionary assignment.
In = {}
data = ['apple'] # This list needed values, otherwise data[-1] threw an error
In [51]: data = list(range(10))
In [53]: data[-1]
print(In) # {51: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]}
# Why were there no values for key 53? (either {53: 'apple'})
I could not really understand what is going on with the 2 lines of code.
I didn't think that this line of code was legal In [51]: data = list(range(10)) and since it was so, why did In [53] value not get assigned after that?
So any explanation or direction to references would be greatly appreciated. Thank you.
Will be answering this question in case anybody had the same questions as me.
Thanks to @Goyo for pointing me towards Variable Annotations which was introduced in Python 3.6
variable: annotation = assignment
This syntax is used to annotate types in variables as compared to using comments (fruit: str = 'apple' vs fruit = 'apple' # type: str).
The value in the annotation field is not strictly enforced and that was the reason why the syntax was legal.
First statement
In [51]: data = list(range(10))
Variable = In [51]
Annotation = data
Assignment = list(range(10))
Second statement
In [53]: data[-1]
Variable = In [53]
Annotation = data[-1]