Python IPython 模块，version_info() 实例源码

def get_ipython_version():
    """Returns the current IPython version"""
    import IPython
    v = None
    if hasattr(IPython, "version_info"):
        v = '.'.join(map(str, IPython.version_info[:3]))
    else:
        try:
            try:
                v = IPython.Release.version
            except:
                try:
                    v = IPython.release.version
                except:
                    pass
        except:
            pass
    return StrictVersion(v)


# PyTango utilities

def test_for(item, min_version=None, callback=extract_version):
    """Test to see if item is importable, and optionally check against a minimum
    version.

    If min_version is given, the default behavior is to check against the
    `__version__` attribute of the item, but specifying `callback` allows you to
    extract the value you are interested in. e.g::

        In [1]: import sys

        In [2]: from IPython.testing.iptest import test_for

        In [3]: test_for('sys', (2,6), callback=lambda sys: sys.version_info)
        Out[3]: True

    """
    try:
        check = import_item(item)
    except (ImportError, RuntimeError):
        # GTK reports Runtime error if it can't be initialized even if it's
        # importable.
        return False
    else:
        if min_version:
            if callback:
                # extra processing step to get version to compare
                check = callback(check)

            return check >= min_version
        else:
            return True

# Global dict where we can store information on what we have and what we don't
# have available at test run time

def test_for(item, min_version=None, callback=extract_version):
    """Test to see if item is importable, and optionally check against a minimum
    version.

    If min_version is given, the default behavior is to check against the
    `__version__` attribute of the item, but specifying `callback` allows you to
    extract the value you are interested in. e.g::

        In [1]: import sys

        In [2]: from IPython.testing.iptest import test_for

        In [3]: test_for('sys', (2,6), callback=lambda sys: sys.version_info)
        Out[3]: True

    """
    try:
        check = import_item(item)
    except (ImportError, RuntimeError):
        # GTK reports Runtime error if it can't be initialized even if it's
        # importable.
        return False
    else:
        if min_version:
            if callback:
                # extra processing step to get version to compare
                check = callback(check)

            return check >= min_version
        else:
            return True

# Global dict where we can store information on what we have and what we don't
# have available at test run time

def install():
    """Register `rlipython` as the default interactive interface for IPython.

    When you run this inside IPython, the preference gets applied to the
    current IPython profile. When run using plain Python, the preference gets
    applied to the default profile.

    Run `uninstall()` if you ever change your mind and want to revert to the
    default IPython behavior.
    """
    if ipython_version < (5,4):
        print("`rliptyhon` will only work with IPython 5.4. or above. Aborting")
        return

    cfg, json_path = get_config()

    installed = cfg.get(app_key, {}).get(shell_key) == rl_config

    if installed:
        print ("Looks like rlipython is already installed.")
        return

    if get_ipython() is None:
        log.warning(DEFAULT_WARNING + json_path)

    with open(json_path, 'w') as f:
        cfg.update({app_key: {shell_key: rl_config}})
        json.dump(cfg, f)

    print("Installation succeeded: enjoy rlipython the next time you run ipython!")

    if sys.platform == "darwin" and sys.version_info[:2] >= (3, 6):
        print(OSX_PY36_GNUREADLINE_WARNING)

def test_for(item, min_version=None, callback=extract_version):
    """Test to see if item is importable, and optionally check against a minimum
    version.

    If min_version is given, the default behavior is to check against the
    `__version__` attribute of the item, but specifying `callback` allows you to
    extract the value you are interested in. e.g::

        In [1]: import sys

        In [2]: from IPython.testing.iptest import test_for

        In [3]: test_for('sys', (2,6), callback=lambda sys: sys.version_info)
        Out[3]: True

    """
    try:
        check = import_item(item)
    except (ImportError, RuntimeError):
        # GTK reports Runtime error if it can't be initialized even if it's
        # importable.
        return False
    else:
        if min_version:
            if callback:
                # extra processing step to get version to compare
                check = callback(check)

            return check >= min_version
        else:
            return True

# Global dict where we can store information on what we have and what we don't
# have available at test run time

def get_python_version():
    return StrictVersion('.'.join(map(str, sys.version_info[:3])))


# IPython utilities

def test_for(item, min_version=None, callback=extract_version):
    """Test to see if item is importable, and optionally check against a minimum
    version.

    If min_version is given, the default behavior is to check against the
    `__version__` attribute of the item, but specifying `callback` allows you to
    extract the value you are interested in. e.g::

        In [1]: import sys

        In [2]: from IPython.testing.iptest import test_for

        In [3]: test_for('sys', (2,6), callback=lambda sys: sys.version_info)
        Out[3]: True

    """
    try:
        check = import_item(item)
    except (ImportError, RuntimeError):
        # GTK reports Runtime error if it can't be initialized even if it's
        # importable.
        return False
    else:
        if min_version:
            if callback:
                # extra processing step to get version to compare
                check = callback(check)

            return check >= min_version
        else:
            return True

# Global dict where we can store information on what we have and what we don't
# have available at test run time