我正在浏览一个包含卵的目录，以便将这些卵添加到sys.path。如果目录中有相同的.egg的两个版本，我只想添加最新的版本。
我有一个正则表达式r ^ (? P < eggName > \ w +) - (? P < eggVersion > (\ d \.]+)-.+\.Egg $从文件名中提取名称和版本。问题是比较版本号，它是一个像2.3.1这样的字符串。
因为我比较字符串，2排序超过10，但这是不正确的版本。
>>> "2.3.1" > "10.1.1"
True
我可以做一些拆分、解析、转换为int等，最终我将得到一个变通方法。但这是Python，不是Java。是否有一种优雅的方法来比较版本字符串?
当前回答
如果你想在一个库版本上创建一个过滤器，你可以使用__version__属性(这里是jwt库的一个例子):
from packaging import version
import jwt
if version.parse(jwt.__version__) < version.parse('2.0.0'):
# TODO: your code
其他回答
简单的few-liner:
import sys
if (sys.version_info.major, sys.version_info.minor) >= (3, 9):
...
else:
...
如果你想在一个库版本上创建一个过滤器，你可以使用__version__属性(这里是jwt库的一个例子):
from packaging import version
import jwt
if version.parse(jwt.__version__) < version.parse('2.0.0'):
# TODO: your code
将版本字符串转换为元组并从那里开始有什么问题?对我来说已经够优雅了
>>> (2,3,1) < (10,1,1)
True
>>> (2,3,1) < (10,1,1,1)
True
>>> (2,3,1,10) < (10,1,1,1)
True
>>> (10,3,1,10) < (10,1,1,1)
False
>>> (10,3,1,10) < (10,4,1,1)
True
@kindall的解决方案是一个简单的例子，说明代码看起来有多好。
我正在寻找一个解决方案，不会增加任何新的依赖。检查以下(Python 3)解决方案:
class VersionManager:
@staticmethod
def compare_version_tuples(
major_a, minor_a, bugfix_a,
major_b, minor_b, bugfix_b,
):
"""
Compare two versions a and b, each consisting of 3 integers
(compare these as tuples)
version_a: major_a, minor_a, bugfix_a
version_b: major_b, minor_b, bugfix_b
:param major_a: first part of a
:param minor_a: second part of a
:param bugfix_a: third part of a
:param major_b: first part of b
:param minor_b: second part of b
:param bugfix_b: third part of b
:return: 1 if a > b
0 if a == b
-1 if a < b
"""
tuple_a = major_a, minor_a, bugfix_a
tuple_b = major_b, minor_b, bugfix_b
if tuple_a > tuple_b:
return 1
if tuple_b > tuple_a:
return -1
return 0
@staticmethod
def compare_version_integers(
major_a, minor_a, bugfix_a,
major_b, minor_b, bugfix_b,
):
"""
Compare two versions a and b, each consisting of 3 integers
(compare these as integers)
version_a: major_a, minor_a, bugfix_a
version_b: major_b, minor_b, bugfix_b
:param major_a: first part of a
:param minor_a: second part of a
:param bugfix_a: third part of a
:param major_b: first part of b
:param minor_b: second part of b
:param bugfix_b: third part of b
:return: 1 if a > b
0 if a == b
-1 if a < b
"""
# --
if major_a > major_b:
return 1
if major_b > major_a:
return -1
# --
if minor_a > minor_b:
return 1
if minor_b > minor_a:
return -1
# --
if bugfix_a > bugfix_b:
return 1
if bugfix_b > bugfix_a:
return -1
# --
return 0
@staticmethod
def test_compare_versions():
functions = [
(VersionManager.compare_version_tuples, "VersionManager.compare_version_tuples"),
(VersionManager.compare_version_integers, "VersionManager.compare_version_integers"),
]
data = [
# expected result, version a, version b
(1, 1, 0, 0, 0, 0, 1),
(1, 1, 5, 5, 0, 5, 5),
(1, 1, 0, 5, 0, 0, 5),
(1, 0, 2, 0, 0, 1, 1),
(1, 2, 0, 0, 1, 1, 0),
(0, 0, 0, 0, 0, 0, 0),
(0, -1, -1, -1, -1, -1, -1), # works even with negative version numbers :)
(0, 2, 2, 2, 2, 2, 2),
(-1, 5, 5, 0, 6, 5, 0),
(-1, 5, 5, 0, 5, 9, 0),
(-1, 5, 5, 5, 5, 5, 6),
(-1, 2, 5, 7, 2, 5, 8),
]
count = len(data)
index = 1
for expected_result, major_a, minor_a, bugfix_a, major_b, minor_b, bugfix_b in data:
for function_callback, function_name in functions:
actual_result = function_callback(
major_a=major_a, minor_a=minor_a, bugfix_a=bugfix_a,
major_b=major_b, minor_b=minor_b, bugfix_b=bugfix_b,
)
outcome = expected_result == actual_result
message = "{}/{}: {}: {}: a={}.{}.{} b={}.{}.{} expected={} actual={}".format(
index, count,
"ok" if outcome is True else "fail",
function_name,
major_a, minor_a, bugfix_a,
major_b, minor_b, bugfix_b,
expected_result, actual_result
)
print(message)
assert outcome is True
index += 1
# test passed!
if __name__ == '__main__':
VersionManager.test_compare_versions()
编辑:添加变量与元组比较。当然，具有元组比较的变体更好，但我正在寻找具有整数比较的变体
类似于标准strverscmp，类似于Mark Byers的解决方案，但使用findall而不是split来避免空大小写。
import re
num_split_re = re.compile(r'([0-9]+|[^0-9]+)')
def try_int(i, fallback=None):
try:
return int(i)
except ValueError:
pass
except TypeError:
pass
return fallback
def ver_as_list(a):
return [try_int(i, i) for i in num_split_re.findall(a)]
def strverscmp_lt(a, b):
a_ls = ver_as_list(a)
b_ls = ver_as_list(b)
return a_ls < b_ls
