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Autogen
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Typical autogen.py code:
browser-kit/curated/www-client/brave-bin/autogen.py
(python source code) def find_release(json_dict, channel="Release"):
releases = filter(
lambda x: x["prerelease"] is False
and x["draft"] is False
and x["name"].startswith(channel)
and not "Android" in x["name"],
json_dict,
)
releases = list(releases)
if not len(releases):
return None
return sorted(releases, key=lambda x: x["tag_name"])[-1]
- Let's start with the
key
argument. It allows to sort an array by specific key;tag_name
in this example.tag_name
is a version number that is stored as a string, so sorting won't work correctly, asmax('10.1', '9.0') == '9.0'
. Better code would bekey=lambda item: tuple(map(int, re.findall('\d+', x["tag_name"])))
, because python sorts tuples of integers correctly. - Next, selecting maximal element by sorting a list and then selecting the rightmost element is not very beautiful.
sorted
can be replaced bymax
:return max(releases, key=extract_version)
max
can return default value, when there are no element, so checkif not len(releases)
becomes needless:return max(releases, key=version, default=None)
x["prerelease"] is False
check is considered unpythonic. Usenot x["prerelease"]
not "Android" in x["name"]
is two operators, that can be combined:"Android" not in x["name"]
- Generator comprehension are considered more pythonic than
filter
.
So, more pythonic version, that works correctly looks like this:
browser-kit/curated/www-client/brave-bin/autogen.py
(python source code) def extract_version(release):
return tuple(map(int, re.findall('\d+', release["tag_name"])))
def find_release(all_releases, channel="Release"):
releases = (
release for release in all_releases
if not release["prerelease"]
and not release["draft"]
and release["name"].startswith(channel)
and "Android" not in release["name"]
)
return max(releases, key=extract_version)