Clean up a few Python 2-isms

[rahulporuri]

This PR removes a few remaining Python 2-isms from the codebase, namely :

• Updating use of super i.e. instead of super(ClassName, self), we just use super(),
• Remove coding cookies from the top of files because on Python 3, utf-8 is the default source code file encoding,
• Remove u-prefix strings because on Python 3 they don't do anything,
• Remove an if/elif/else conditional which was always true for python 3.

Note to reviewer : Each commit in this PR makes one and only one kind of change (listed above) so reviewing this PR commit-by-commit will be straightforward.

TODO:

• Add unit tests and/or doctests in docstrings
• Add docstrings and API docs for any new/modified user-facing classes and functions
• New/modified features documented in docs/tutorial.rst
• Changes documented in docs/release.rst
• AppVeyor and Travis CI passes
• Test coverage is 100% (Coveralls passes)

[pep8speaks]

Hello @rahulporuri! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

There are currently no PEP 8 issues detected in this Pull Request. Cheers! 🍻

Comment last updated at 2020-09-18 19:27:16 UTC

[clbarnes]

Could you also remove the references to python <3 in the requirements files? I was going to make my own PR but it should just go here. Patch file was

From 4510eb512e7011e80f14dbdb08fe869931364ebf Mon Sep 17 00:00:00 2001
From: Chris Barnes <[email protected]>
Date: Fri, 11 Sep 2020 17:54:04 +0100
Subject: [PATCH] Remove python<3.0 references from requirements

---
 requirements_dev_minimal.txt  | 4 +---
 requirements_dev_numpy.txt    | 4 +---
 requirements_dev_optional.txt | 2 +-
 3 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/requirements_dev_minimal.txt b/requirements_dev_minimal.txt
index 9aefb92..7928558 100644
--- a/requirements_dev_minimal.txt
+++ b/requirements_dev_minimal.txt
@@ -5,6 +5,4 @@ numcodecs==0.6.4
 msgpack-python==0.5.6
 setuptools-scm==3.3.3
 # test requirements
-pytest==5.2.0; python_version > '3.0'
-# don't let pyup change this, needed until we drop support for py27
-pytest==4.6.5; python_version < '3.0' # pyup: ignore
+pytest==5.2.0
diff --git a/requirements_dev_numpy.txt b/requirements_dev_numpy.txt
index b5d87c4..f2ac012 100644
--- a/requirements_dev_numpy.txt
+++ b/requirements_dev_numpy.txt
@@ -1,6 +1,4 @@
 # Break this out into a separate file to allow testing against
 # different versions of numpy. This file should pin to the latest
 # numpy version.
-numpy==1.17.2; python_version > '3.0'
-# don't let pyup change this, needed until we drop support for py27
-numpy==1.16.4; python_version < '3.0' # pyup: ignore
+numpy==1.17.2
diff --git a/requirements_dev_optional.txt b/requirements_dev_optional.txt
index 5777ad5..95a9ee5 100644
--- a/requirements_dev_optional.txt
+++ b/requirements_dev_optional.txt
@@ -18,4 +18,4 @@ pytest-cov==2.7.1
 pytest-doctestplus==0.4.0
 pytest-remotedata==0.3.2
 h5py==2.10.0
-s3fs==0.3.4; python_version > '3.0'
+s3fs==0.3.4
-- 
2.28.0

[rahulporuri]

@clbarnes I've addressed your comment about the requirements files.

[Carreau]

Rebased to fix conflicts.

[Carreau]

I believe the coverage failure is due the the decrease in number of LOC infiles that are not 100% covered.

As the total number of lines decrease, if the number of uncovered lines decrease we get a relative change of percentage, leading to failure, even if no actual code get un-covered.

+1

[rahulporuri]

Thanks @Carreau for the fixes. I noticed in the middle of the week that there were conflicts and I was hoping to make time to address them this weekend :D

[Carreau]

I noticed in the middle of the week that there were conflicts and I was hoping to make time to address them this weekend :D

No worries, I was on other things so it was relatively straightforward. Still like to get other more senior core dev approval on this.