2f0b3ea362
The automated python2 -> python3 converter creates some suboptimal
code patterns in some cases, notably in its handling of dicts.
This commit handles the following cases:
* "if x in list(y.keys()):" => "if x in y:"
The original code is neuters the O(1) lookup effeciency of a dict
by turning it into a list. This occurs a O(n) in converting it to
a list and then another O(n) for the lookup. When done in a loop,
this becomes O(n * m) rather than the optimal O(m).
* "for x in list(y.keys()):" => "for x in y:" OR "for x in list(y):"
A dict (y in these cases) operates as an iterator over keys in the
dict by default. This makes the entire "list(y.keys())" dance
redundant _in most cases_. In a some cases, scour modifies the
dict while iterating over it and in those cases, we need a
"list(y)" (but not a "y.keys()").
The benefit of this differs between python2 and python3. In
python3, we basically "only" avoid function call. In python2,
y.keys() generates a list, so here we avoid generating a
"throw-away list".
The test suite succeed both with "python testscour.py" and "python3
testscour.py" (used 2.7.14+ and 3.6.4 from Debian testing).
On a 341kB flame-graph generated by "nytprof" (a perl profiler), this
commit changes the runtimes of scour from the range 3.39s - 3.45s to
3.27s - 3.35s making it roughly 3% faster in this case (YMMV,
particularly with different input). The timings were recorded using
the following command line:
time PYTHONPATH=. python3 -m scour.scour --enable-id-stripping \
--shorten-ids --indent=none --enable-comment-stripping
-i input.svg -o output.svg
This was used 5 times with and 5 times without the patch picking the
worst and best time to define the range. The runtime test was only
preformed on python3.
All changed lines where found with:
grep -rE ' in list[(].*[.]keys[(][)][)]:'
Signed-off-by: Niels Thykier <niels@thykier.net>
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|---|---|---|
| scour | ||
| unittests | ||
| .gitignore | ||
| .travis.yml | ||
| CONTRIBUTING.md | ||
| HISTORY.md | ||
| LICENSE | ||
| Makefile | ||
| README.md | ||
| scour.sublime-project | ||
| setup.py | ||
| testcss.py | ||
| testscour.py | ||
| tox.ini | ||
Scour
Scour is an SVG optimizer/cleaner that reduces the size of scalable vector graphics by optimizing structure and removing unnecessary data written in Python.
It can be used to create streamlined vector graphics suitable for web deployment, publishing/sharing or further processing.
The goal of Scour is to output a file that renderes identically at a fraction of the size by removing a lot of redundant information created by most SVG editors. Optimization options are typically lossless but can be tweaked for more agressive cleaning.
Scour is open-source and licensed under Apache License 2.0.
Scour was originally developed by Jeff "codedread" Schiller and Louis Simard in in 2010. The project moved to GitLab in 2013 an is now maintained by Tobias "oberstet" Oberstein and Eduard "Ede_123" Braun.
Installation
Scour requires Python 2.7 or 3.3+. Further, for installation, pip should be used.
To install the latest release of Scour from PyPI:
pip install scour
To install the latest trunk version (which might be broken!) from GitHub:
pip install https://github.com/codedread/scour/archive/master.zip
Usage
Standard:
scour -i input.svg -o output.svg
Better (for older versions of Internet Explorer):
scour -i input.svg -o output.svg --enable-viewboxing
Maximum scrubbing:
scour -i input.svg -o output.svg --enable-viewboxing --enable-id-stripping \
--enable-comment-stripping --shorten-ids --indent=none
Maximum scrubbing and a compressed SVGZ file:
scour -i input.svg -o output.svgz --enable-viewboxing --enable-id-stripping \
--enable-comment-stripping --shorten-ids --indent=none