runtimequestion 297 Packaging & Databases · medium
Expand ~= and wildcard specifiers
A simple version checker only understands >=, <, == and != with plain versions. Write expand_spec(spec) to rewrite the two shorthand forms into conditions it understands. ~=X.Y (compatible release) means >=X.Y and below the next release of the part before the last: ~=2.2 → >=2.2,<3, ~=1.4.5 → >=1.4.5,<1.5. ==X.Y.* means any version starting X.Y: >=X.Y,<X.(Y+1).
Function
expand_spec(spec)specconditions joined by commas, with or without spaces, e.g.
"~=1.4.5, !=1.4.7"Returnsthe conditions joined by
, with no spaces, shorthand expanded in place, others unchanged; "" for ""Raises
ValueError for ~= with a one-part version (~=2), which PEP 440 does not allowExamples
callexpand_spec('~=2.2')returns'>=2.2,<3'
callexpand_spec('~=1.4.5, !=1.4.7')returns'>=1.4.5,<1.5,!=1.4.7'
callexpand_spec('==3.1.*')returns'>=3.1,<3.2'