Fixed "Debugging memory leaks with Guppy"( issue #4285)

[sakshamb2113]

The section referring to guppy(for python 2.7) for debugging memory leaks now only refers to muppy(for python 3). Issue #4285.

[sakshamb2113]

@noviluni please review

[codecov]

Codecov Report

Merging #4343 into master will increase coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #4343      +/-   ##
==========================================
+ Coverage   84.75%   84.78%   +0.02%     
==========================================
  Files         165      164       -1     
  Lines        9898     9883      -15     
  Branches     1470     1469       -1     
==========================================
- Hits         8389     8379      -10     
+ Misses       1253     1248       -5     
  Partials      256      256

Impacted Files	Coverage Δ
scrapy/extensions/telnet.py	81.66% <ø> (+0.12%)	⬆️
scrapy/utils/trackref.py	82.85% <0%> (ø)	⬆️
scrapy/downloadermiddlewares/chunked.py

[noviluni]

Hi @Gallaecio

I've seen that after removing this we should probably delete these lines:

try:
    import guppy
    hpy = guppy.hpy()
except ImportError:
    hpy = None

from the scrapy/extensions/telnet.py.

Do you agree?

[wRAR]

@sakshamb2113 can you please update this to resolve the conflict?

[sakshamb2113]

sure

[sakshamb2113]

@wRAR what should we do about the "hpy" key of telnet_vars in telnet.py ?

[Gallaecio]

Pending one small change.