PipRequirement

Complexity

Total Complexity

3

Size/Duplication

Total Lines	49
Duplicated Lines	0 %

Importance

Changes	2
Bugs	0	Features	0

3 Methods

Rating	Name	Duplication	Size	Complexity
A	__init__()	0	17	1
A	install_command()	0	10	1
A	is_installed()	0	14	1

from coalib.bears.requirements.PackageRequirement import PackageRequirement
import subprocess


class PipRequirement(PackageRequirement):
    """
    This class is a subclass of ``PackageRequirement``, and helps specifying
    requirements from ``pip``, without using the manager name.
    """

    def __init__(self, package, version=""):
        """
        Constructs a new ``PipRequirement``, using the ``PackageRequirement``
        constructor.

        >>> pr = PipRequirement('setuptools', '19.2')
        >>> pr.manager
        'pip'
        >>> pr.package
        'setuptools'
        >>> pr.version
        '19.2'

        :param package: A string with the name of the package to be installed.
        :param version: A version string. Leave empty to specify latest version.
        """
        PackageRequirement.__init__(self, 'pip', package, version)

    def install_command(self):
        """
        Creates the installation command for the instance of the class.

        >>> PipRequirement('setuptools', '19.2').install_command()
        'pip install setuptools==19.2'

        :param return: A string with the installation command.
        """
        return "pip install {}=={}".format(self.package, self.version)

    def is_installed(self):
        """
        Checks if the dependency is installed.

        >>> PipRequirement('pip').is_installed()
        True

        >>> PipRequirement('some_package').is_installed()
        False

        :param return: True if dependency is installed, false otherwise.
        """
        return not subprocess.call(['pip', 'show', self.package],
                                   stdout=subprocess.DEVNULL)