False-positive "old-division" (W1619) on explicit float division

[obi1kenobi]

My understanding is that W1619 (old-division) is supposed to check for PEP238 safety, and help users avoid unfortunate surprises when division on integers becomes true division. However, I believe that if the number being divided is a float, PEP238 does not change the division semantics, and therefore the following code (call it repro.py) should run the same in both Python 2 and 3.

x = float(4) / 2
print(x)

Possibly related to #2887 and #2803

Steps to reproduce

1. Create the repro.py file described above.
2. Run pylint --reports=no --disable=all --enable=old-division repro.py

Current behavior

$ pylint --reports=no --disable=all --enable=old-division repro.py 
************* Module repro
repro.py:1:4: W1619: division w/o __future__ statement (old-division)

-----------------------------------
Your code has been rated at 5.00/10

Expected behavior

Since the division is explicitly on a float-typed number, pylint reports no issues.

pylint --version output

Both the newest 2.x and the newest 1.x seem to be affected:

$ pylint --version
pylint 2.3.1
astroid 2.2.5
Python 3.6.8 (default, Mar 14 2019, 21:00:19) 
[GCC 4.2.1 Compatible Apple LLVM 10.0.0 (clang-1000.11.45.5)]

$ pylint --version
No config file found, using default configuration
pylint 1.9.5, 
astroid 1.6.6
Python 3.6.8 (default, Mar 14 2019, 21:00:19) 
[GCC 4.2.1 Compatible Apple LLVM 10.0.0 (clang-1000.11.45.5)]

[PCManticore]

Thanks for the report, it definitely makes sense.

[bojanbg]

This still raises W1619 with pylint 2.4.4:

print(100 * float(5) / 10)

My mental model was that pylint can recognize that the numerator is a float.