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			270 lines
		
	
	
	
		
			9.4 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			270 lines
		
	
	
	
		
			9.4 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
"""Class and functions dealing with dependencies between distributions.
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This module provides a DependencyGraph class to represent the
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dependencies between distributions.  Auxiliary functions can generate a
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graph, find reverse dependencies, and print a graph in DOT format.
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"""
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import sys
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from io import StringIO
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from packaging.errors import PackagingError
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from packaging.version import VersionPredicate, IrrationalVersionError
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__all__ = ['DependencyGraph', 'generate_graph', 'dependent_dists',
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           'graph_to_dot']
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class DependencyGraph:
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    """
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    Represents a dependency graph between distributions.
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    The dependency relationships are stored in an ``adjacency_list`` that maps
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    distributions to a list of ``(other, label)`` tuples where  ``other``
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    is a distribution and the edge is labeled with ``label`` (i.e. the version
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    specifier, if such was provided). Also, for more efficient traversal, for
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    every distribution ``x``, a list of predecessors is kept in
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    ``reverse_list[x]``. An edge from distribution ``a`` to
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    distribution ``b`` means that ``a`` depends on ``b``. If any missing
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    dependencies are found, they are stored in ``missing``, which is a
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    dictionary that maps distributions to a list of requirements that were not
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    provided by any other distributions.
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    """
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    def __init__(self):
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        self.adjacency_list = {}
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        self.reverse_list = {}
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        self.missing = {}
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    def add_distribution(self, distribution):
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        """Add the *distribution* to the graph.
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        :type distribution: :class:`packaging.database.Distribution` or
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                            :class:`packaging.database.EggInfoDistribution`
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        """
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        self.adjacency_list[distribution] = []
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        self.reverse_list[distribution] = []
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        self.missing[distribution] = []
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    def add_edge(self, x, y, label=None):
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        """Add an edge from distribution *x* to distribution *y* with the given
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        *label*.
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        :type x: :class:`packaging.database.Distribution` or
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                 :class:`packaging.database.EggInfoDistribution`
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        :type y: :class:`packaging.database.Distribution` or
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                 :class:`packaging.database.EggInfoDistribution`
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        :type label: ``str`` or ``None``
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        """
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        self.adjacency_list[x].append((y, label))
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        # multiple edges are allowed, so be careful
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        if x not in self.reverse_list[y]:
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            self.reverse_list[y].append(x)
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    def add_missing(self, distribution, requirement):
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        """
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        Add a missing *requirement* for the given *distribution*.
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        :type distribution: :class:`packaging.database.Distribution` or
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                            :class:`packaging.database.EggInfoDistribution`
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        :type requirement: ``str``
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        """
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        self.missing[distribution].append(requirement)
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    def _repr_dist(self, dist):
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        return '%r %s' % (dist.name, dist.version)
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    def repr_node(self, dist, level=1):
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        """Prints only a subgraph"""
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        output = []
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        output.append(self._repr_dist(dist))
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        for other, label in self.adjacency_list[dist]:
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            dist = self._repr_dist(other)
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            if label is not None:
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                dist = '%s [%s]' % (dist, label)
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            output.append('    ' * level + str(dist))
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            suboutput = self.repr_node(other, level + 1)
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            subs = suboutput.split('\n')
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            output.extend(subs[1:])
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        return '\n'.join(output)
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    def __repr__(self):
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        """Representation of the graph"""
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        output = []
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        for dist, adjs in self.adjacency_list.items():
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            output.append(self.repr_node(dist))
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        return '\n'.join(output)
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def graph_to_dot(graph, f, skip_disconnected=True):
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    """Writes a DOT output for the graph to the provided file *f*.
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    If *skip_disconnected* is set to ``True``, then all distributions
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    that are not dependent on any other distribution are skipped.
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    :type f: has to support ``file``-like operations
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    :type skip_disconnected: ``bool``
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    """
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    disconnected = []
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    f.write("digraph dependencies {\n")
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    for dist, adjs in graph.adjacency_list.items():
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        if len(adjs) == 0 and not skip_disconnected:
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            disconnected.append(dist)
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        for other, label in adjs:
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            if not label is None:
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                f.write('"%s" -> "%s" [label="%s"]\n' %
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                                            (dist.name, other.name, label))
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            else:
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                f.write('"%s" -> "%s"\n' % (dist.name, other.name))
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    if not skip_disconnected and len(disconnected) > 0:
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        f.write('subgraph disconnected {\n')
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        f.write('label = "Disconnected"\n')
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        f.write('bgcolor = red\n')
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        for dist in disconnected:
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            f.write('"%s"' % dist.name)
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            f.write('\n')
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        f.write('}\n')
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    f.write('}\n')
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def generate_graph(dists):
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    """Generates a dependency graph from the given distributions.
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    :parameter dists: a list of distributions
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    :type dists: list of :class:`packaging.database.Distribution` and
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                 :class:`packaging.database.EggInfoDistribution` instances
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    :rtype: a :class:`DependencyGraph` instance
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    """
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    graph = DependencyGraph()
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    provided = {}  # maps names to lists of (version, dist) tuples
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    # first, build the graph and find out the provides
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    for dist in dists:
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        graph.add_distribution(dist)
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        provides = (dist.metadata['Provides-Dist'] +
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                    dist.metadata['Provides'] +
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                    ['%s (%s)' % (dist.name, dist.version)])
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        for p in provides:
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            comps = p.strip().rsplit(" ", 1)
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            name = comps[0]
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            version = None
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            if len(comps) == 2:
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                version = comps[1]
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                if len(version) < 3 or version[0] != '(' or version[-1] != ')':
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                    raise PackagingError('distribution %r has ill-formed'
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                                         'provides field: %r' % (dist.name, p))
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                version = version[1:-1]  # trim off parenthesis
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            if name not in provided:
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                provided[name] = []
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            provided[name].append((version, dist))
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    # now make the edges
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    for dist in dists:
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        requires = dist.metadata['Requires-Dist'] + dist.metadata['Requires']
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        for req in requires:
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            try:
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                predicate = VersionPredicate(req)
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            except IrrationalVersionError:
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                # XXX compat-mode if cannot read the version
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                name = req.split()[0]
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                predicate = VersionPredicate(name)
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            name = predicate.name
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            if name not in provided:
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                graph.add_missing(dist, req)
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            else:
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                matched = False
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                for version, provider in provided[name]:
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                    try:
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                        match = predicate.match(version)
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                    except IrrationalVersionError:
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                        # XXX small compat-mode
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                        if version.split(' ') == 1:
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                            match = True
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                        else:
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                            match = False
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                    if match:
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                        graph.add_edge(dist, provider, req)
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                        matched = True
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                        break
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                if not matched:
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                    graph.add_missing(dist, req)
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    return graph
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def dependent_dists(dists, dist):
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    """Recursively generate a list of distributions from *dists* that are
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    dependent on *dist*.
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    :param dists: a list of distributions
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    :param dist: a distribution, member of *dists* for which we are interested
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    """
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    if dist not in dists:
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        raise ValueError('given distribution %r is not a member of the list' %
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                         dist.name)
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    graph = generate_graph(dists)
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    dep = [dist]  # dependent distributions
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    fringe = graph.reverse_list[dist]  # list of nodes we should inspect
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    while not len(fringe) == 0:
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        node = fringe.pop()
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        dep.append(node)
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        for prev in graph.reverse_list[node]:
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            if prev not in dep:
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                fringe.append(prev)
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    dep.pop(0)  # remove dist from dep, was there to prevent infinite loops
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    return dep
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def main():
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    # XXX move to run._graph
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    from packaging.database import get_distributions
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    tempout = StringIO()
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    try:
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        old = sys.stderr
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        sys.stderr = tempout
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        try:
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            dists = list(get_distributions(use_egg_info=True))
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            graph = generate_graph(dists)
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        finally:
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            sys.stderr = old
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    except Exception as e:
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        tempout.seek(0)
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        tempout = tempout.read()
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        print('Could not generate the graph')
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        print(tempout)
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        print(e)
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        sys.exit(1)
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    for dist, reqs in graph.missing.items():
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        if len(reqs) > 0:
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            print("Warning: Missing dependencies for %r:" % dist.name,
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                  ", ".join(reqs))
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    # XXX replace with argparse
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    if len(sys.argv) == 1:
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        print('Dependency graph:')
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        print('   ', repr(graph).replace('\n', '\n    '))
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        sys.exit(0)
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    elif len(sys.argv) > 1 and sys.argv[1] in ('-d', '--dot'):
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        if len(sys.argv) > 2:
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            filename = sys.argv[2]
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        else:
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            filename = 'depgraph.dot'
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        with open(filename, 'w') as f:
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            graph_to_dot(graph, f, True)
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        tempout.seek(0)
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        tempout = tempout.read()
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        print(tempout)
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        print('Dot file written at %r' % filename)
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        sys.exit(0)
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    else:
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        print('Supported option: -d [filename]')
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        sys.exit(1)
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