vermin 0.4.4

Concurrently detect the minimum Python versions needed to run code

Vermin

Concurrently detect the minimum Python versions needed to run code. Additionally, since the code is vanilla Python, and it doesn’t have any external dependencies, it works with v2.7+ and v3+.

It functions by parsing Python code into an abstract syntax tree (AST), which it traverses and matches against internal dictionaries with 802 rules divided into 116 modules, 540 classes/functions/constants members of modules, 142 kwargs of functions, and 4 strftime directives. Including looking for v2/v3 print expr and print(expr), long, f-strings, boolean constants, "..".format(..), imports (import X, from X import Y, from X import *), function calls wrt. name and kwargs, and strftime + strptime directives used. It tries to detect and ignore user-defined functions, classes, arguments, and variables with names that clash with library- defined symbols.

Usage

It is fairly straightforward to use Vermin:

./vermin.py /path/to/your/project

Or via PyPi:

% pip install vermin
% vermin /path/to/your/project

When using continuous integration (CI) tools, like Travis CI, Vermin can be used to check that the minimum required versions didn’t change. The following is an exerpt:

install:
- ./setup_virtual_env.sh
- pip install vermin
script:
- vermin -t=2.7 -t=3 project_package otherfile.py

Examples

% ./vermin.py
Vermin 0.4.4
Usage: ./vermin.py [options] <python source files and folders..>

Options:
  -q      Quite mode. It only prints the final versions verdict.
  -v..    Verbosity level 1 to 3. -v, -vv, and -vvv shows increasingly more information.
          -v will show the individual versions required per file, -vv will additionally
          show which modules, functions etc. that constitutes the requirements.
  -t=V    Target version that files must abide by. Can be specified once or twice.
          If not met Vermin will exit with code 1.
  -p=N    Use N concurrent processes to analyze files (defaults to all cores = 8).
  -i      Ignore incompatible version warnings.
  -d      Dump AST node visits.

% ./vermin.py -q vermin
Minimum required versions: 2.7, 3.0

% ./vermin.py -q -t=3.3 vermin
Minimum required versions: 2.7, 3.0
Target versions not met:   3.3
% echo $?
1

% ./vermin.py -v examples
Detecting python files..
Analyzing 6 files using 8 processes..
             /path/to/examples/formatv2.py
2.7, 3.2     /path/to/examples/argparse.py
2.7, 3.0     /path/to/examples/formatv3.py
2.0, 3.0     /path/to/examples/printv3.py
!2, 3.4      /path/to/examples/abc.py
             /path/to/examples/unknown.py
Minimum required versions:   3.4
Incompatible versions:         2

% ./vermin.py -vv /path/to/examples/abc.py
Detecting python files..
Analyzing using 8 processes..
!2, 3.4      /path/to/examples/abc.py
  'abc' requires (2.6, 3.0)
  'abc.ABC' requires (None, 3.4)

Minimum required versions: 3.4
Incompatible versions:     2

Contributing

Contributions are very welcome, especially adding and updating detection rules of modules, functions, classes etc. to cover as many Python versions as possible. For PRs, make sure to keep the code vanilla Python and run make test first. Note that code must be remain valid and working on Python v2.7+ and v3+.