Utilities API

OS Utilities

PGMob will try to abstract OS commands using classes that provide support for a specific OS.

class pgmob.os.OSCommandResult(command: str)

Results of the OS command execution

exit_code

command exit code

Type:

int

text

stdout and stderr together

Type:

str

raise_for_error()

Raises an exception when exist code is not 0.

Raises:

PostgresShellCommandError – when exit code is not 0

class pgmob.os.ShellEnv

Shell-like command line operations (/bin/sh)

static get_os_command_wrapper() → str

Returns a wrapper for an OS command used by run_os_command method

Returns:

wrapper for an OS command

Return type:

str

static join_path(*args) → str

Joins path according to the local OS rules. Deals with URLs and Posix paths

Parameters:

*args – paths that need to be joined

Returns:

Joined path string

Return type:

str

static quote(cmd: str) → str

Quotes command line argument for a shell function

Parameters:

cmd (str) – command line argument to escape

Returns:

quoted command line argument

Return type:

str

General Utilities

Internal module utilities.

class pgmob.util.Version(version)

Version object. Allows to track major, minor, build and revision versions, left to right.

property base_version: str

The “base version” of the version.

>>> Version("1.2.3").base_version
'1.2.3'
>>> Version("1.2.3+abc").base_version
'1.2.3'
>>> Version("1!1.2.3+abc.dev1").base_version
'1!1.2.3'

The “base version” is the public version of the project without any pre or post release markers.

property dev: int | None

The development number of the version.

>>> print(Version("1.2.3").dev)
None
>>> Version("1.2.3.dev1").dev
1

property epoch: int

The epoch of the version.

>>> Version("2.0.0").epoch
0
>>> Version("1!2.0.0").epoch
1

property is_devrelease: bool

Whether this version is a development release.

>>> Version("1.2.3").is_devrelease
False
>>> Version("1.2.3.dev1").is_devrelease
True

property is_postrelease: bool

Whether this version is a post-release.

>>> Version("1.2.3").is_postrelease
False
>>> Version("1.2.3.post1").is_postrelease
True

property is_prerelease: bool

Whether this version is a pre-release.

>>> Version("1.2.3").is_prerelease
False
>>> Version("1.2.3a1").is_prerelease
True
>>> Version("1.2.3b1").is_prerelease
True
>>> Version("1.2.3rc1").is_prerelease
True
>>> Version("1.2.3dev1").is_prerelease
True

property local: str | None

The local version segment of the version.

>>> print(Version("1.2.3").local)
None
>>> Version("1.2.3+abc").local
'abc'

property major: int

The first item of release or 0 if unavailable.

>>> Version("1.2.3").major
1

property micro: int

The third item of release or 0 if unavailable.

>>> Version("1.2.3").micro
3
>>> Version("1").micro
0

property minor: int

The second item of release or 0 if unavailable.

>>> Version("1.2.3").minor
2
>>> Version("1").minor
0

property post: int | None

The post-release number of the version.

>>> print(Version("1.2.3").post)
None
>>> Version("1.2.3.post1").post
1

property pre: Tuple[str, int] | None

The pre-release segment of the version.

>>> print(Version("1.2.3").pre)
None
>>> Version("1.2.3a1").pre
('a', 1)
>>> Version("1.2.3b1").pre
('b', 1)
>>> Version("1.2.3rc1").pre
('rc', 1)

property public: str

The public portion of the version.

>>> Version("1.2.3").public
'1.2.3'
>>> Version("1.2.3+abc").public
'1.2.3'
>>> Version("1.2.3+abc.dev1").public
'1.2.3'

property release: Tuple[int, ...]

The components of the “release” segment of the version.

>>> Version("1.2.3").release
(1, 2, 3)
>>> Version("2.0.0").release
(2, 0, 0)
>>> Version("1!2.0.0.post0").release
(2, 0, 0)

Includes trailing zeroes but not the epoch or any pre-release / development / post-release suffixes.

pgmob.util.get_shell(name: str) → str

Retrieves shell code from a file in a ‘shell’ folder

Parameters:

name (str) – file name w/o extension

Returns:

file contents

Return type:

str

pgmob.util.get_sql(name: str, version: Version | None = None) → SQL

Retrieves SQL code from a file in a ‘sql’ folder

Parameters:

• name (str) – file name w/o extension”

• version (Version) – specific Postgres version to search for

Returns:

sql code

Return type:

SQL

pgmob.util.group_by(key: Callable[[...], str], seq: Sequence[_T]) → Dict[str, List[_T]]

Groups a list by key

Parameters:

• key – lambda function to extract the key from a value

• seq – input items

Returns:

a dictionary grouped by keys

Return type:

dict