5.1. sourceinfo.__init__

Common definitions for the package pysourceinfo.

5.1.1. Module

‘pysourceinfo’ - Python RTTI based on ‘inspect’

5.1.2. Constants

5.1.2.1. Search Path Resolution

The resolution of the path variables for loaded modules is not provided by the Python interpreter - at least not as a simple usable variable. The resolution from the PYTHONPATH / sys.path depends on the load mechanism, and potentially on the current entries in the sys.path variable. When loaded by a filepath this could be an arbitrary filesystem path, or a memory block. Due to the variety of possible load mechanisms of Python and the lack of an interpreter variable, the implementation relies on the sys.path variable by checking these as a matching path-prefix.

The sys.path variable could be populated with arbitrary paths and redundancies, the python interpreter adds the startup directory by default into the position sys.path[0]. So this algorithm is by definition only as acurate, as the current sys.path variable reflects the actual load-prefixes. Therefore the pysourceinfo package defines constants that control the evaluation strategy of the package path from the search tpath list PYTHONPATH/sys.path. In case of one matching path-prefix, this values have no effect. The constants help for the expected resolution in case of multiple matches, with remaining possible in-accuracies. The controlling constants are:

  • P_FIRST: first matched path-prefix

  • P_IGNORE0: starts with element 1, ignores element 0

  • P_LAST: last matched path-prefix

  • P_LONGEST: longest matched path-prefix

  • P_SHORTEST: longest matched path-prefix

The interfaces supporting path resolution provide the parameter presolve for individual setting for each call.

The default value is stored in the package variable with the default value P_FIRST.

1
sourceinfo.presolve = P_FIRST

The effect of the search strategy is two-folded,

  1. resolution of the path-prefix

  2. resolution of relative sub-paths

The constants are consistently defining the strategy for the path-prefix only, the resulting strategy for the sub-path resolution is therefore reziprocal. The constants have the following effect.

  • P_FIRST: results in arbitrary matching sub-path of the first path

  • P_LAST: results in arbitrary matching sub-path of the last path

  • P_LONGEST: results in shortest possible matching sub-path

  • P_SHORTEST: results in longest possible matching sub-path

The resolution of absolute filenames of modules is not effected by the constants.

For the shared implementation refer to matchpath().

5.1.2.2. File Types

The following constants are defined as common and independent constants identifying file types. These are supported on all platforms for Python2 and Python3, where the introduced __pycache__ is handeled.

The values are adapted to the standard enumeration and continued consistently over spanning the releases.

The values MT_COMPILED_OPT1 and MT_COMPILED_OPT2 are in the current version partially ambiguous due to the lack of file-content analysis.

  • MT_UNKNOWN

    1
    MT_UNKNOWN = 0

  • MT_SOURCE

    1
    MT_SOURCE = 1  #: same value as PY_SOURCE = 1

  • MT_COMPILED

    1
    MT_COMPILED = 2  #: same value as PY_COMPILED = 2

  • MT_EXTENSION

    1
    MT_EXTENSION = 3  # : same value as C_EXTENSION = 3

  • MT_DIRECTORY

    1
    MT_DIRECTORY = 5  # : same value as PKG_DIRECTORY = 5

  • MT_BUILTIN

    1
    MT_BUILTIN = 6  # : same value as C_BUILTIN = 6

  • MT_FROZEN

    1
    MT_FROZEN = 7  # : same value as PY_FROZEN = 7

  • MT_COMPILED_OPT1

    1
    MT_COMPILED_OPT1 = 10  # : PY_COMPILED | <opt1> # 2 | 8

  • MT_COMPILED_OPT2

    1
    MT_COMPILED_OPT2 = 18  # : PY_COMPILED | <opt2> # 2 | 16

  • MT_COMPILED_DEBUG

    1
    MT_COMPILED_DEBUG = 34  # : PY_COMPILED | 0 # 2 | 32

5.1.2.3. Miscelaneous

Shared control variables for pysourceinfo:

  • debug

  • verbose

5.1.3. Exceptions

class sourceinfo.__init__.SourceInfoError(*args, **kw)[source]

Common parent exception for the pysourceinfo package.