comparison contrib/import-checker.py @ 20038:c65a6937b828

import-checker: try a little harder to show fewer cycles

This makes sure that all cycles begin with the lexicographically first
module, so that we're less likely to show overlapping cycles in the
final analysis.

20037:957b43371928

            if cyclekey(cycle) not in ignore:
                raise CircularImport(cycle)
            continue
        check_one_mod(i, imports, path=path, ignore=ignore)


def find_cycles(imports):
    """Find cycles in an already-loaded import graph.

    >>> imports = {'top.foo': ['bar', 'os.path', 'qux'],
    ...            'top.bar': ['baz', 'sys'],
    ...            'top.baz': ['foo'],
    ...            'top.qux': ['foo']}
    >>> print '\\n'.join(sorted(find_cycles(imports)))
    top.bar -> top.baz -> top.foo -> top.bar
    top.foo -> top.qux -> top.foo
    """
    cycles = {}
    for mod in sorted(imports.iterkeys()):
        try:
            check_one_mod(mod, imports, ignore=cycles)

20038:c65a6937b828

            if cyclekey(cycle) not in ignore:
                raise CircularImport(cycle)
            continue
        check_one_mod(i, imports, path=path, ignore=ignore)

def rotatecycle(cycle):
    """arrange a cycle so that the lexicographically first module listed first

    >>> rotatecycle(['foo', 'bar', 'foo'])
    ['bar', 'foo', 'bar']
    """
    lowest = min(cycle)
    idx = cycle.index(lowest)
    return cycle[idx:] + cycle[1:idx] + [lowest]

def find_cycles(imports):
    """Find cycles in an already-loaded import graph.

    >>> imports = {'top.foo': ['bar', 'os.path', 'qux'],
    ...            'top.bar': ['baz', 'sys'],
    ...            'top.baz': ['foo'],
    ...            'top.qux': ['foo']}
    >>> print '\\n'.join(sorted(find_cycles(imports)))
    top.bar -> top.baz -> top.foo -> top.bar -> top.bar
    top.foo -> top.qux -> top.foo -> top.foo
    """
    cycles = {}
    for mod in sorted(imports.iterkeys()):
        try:
            check_one_mod(mod, imports, ignore=cycles)