init

.venv/lib/python3.8/site-packages/mccabe.py

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+""" Meager code path measurement tool.
+    Ned Batchelder
+    http://nedbatchelder.com/blog/200803/python_code_complexity_microtool.html
+    MIT License.
+"""
+from __future__ import with_statement
+
+import optparse
+import sys
+import tokenize
+
+from collections import defaultdict
+try:
+    import ast
+    from ast import iter_child_nodes
+except ImportError:   # Python 2.5
+    from flake8.util import ast, iter_child_nodes
+
+__version__ = '0.6.1'
+
+
+class ASTVisitor(object):
+    """Performs a depth-first walk of the AST."""
+
+    def __init__(self):
+        self.node = None
+        self._cache = {}
+
+    def default(self, node, *args):
+        for child in iter_child_nodes(node):
+            self.dispatch(child, *args)
+
+    def dispatch(self, node, *args):
+        self.node = node
+        klass = node.__class__
+        meth = self._cache.get(klass)
+        if meth is None:
+            className = klass.__name__
+            meth = getattr(self.visitor, 'visit' + className, self.default)
+            self._cache[klass] = meth
+        return meth(node, *args)
+
+    def preorder(self, tree, visitor, *args):
+        """Do preorder walk of tree using visitor"""
+        self.visitor = visitor
+        visitor.visit = self.dispatch
+        self.dispatch(tree, *args)  # XXX *args make sense?
+
+
+class PathNode(object):
+    def __init__(self, name, look="circle"):
+        self.name = name
+        self.look = look
+
+    def to_dot(self):
+        print('node [shape=%s,label="%s"] %d;' % (
+            self.look, self.name, self.dot_id()))
+
+    def dot_id(self):
+        return id(self)
+
+
+class PathGraph(object):
+    def __init__(self, name, entity, lineno, column=0):
+        self.name = name
+        self.entity = entity
+        self.lineno = lineno
+        self.column = column
+        self.nodes = defaultdict(list)
+
+    def connect(self, n1, n2):
+        self.nodes[n1].append(n2)
+        # Ensure that the destination node is always counted.
+        self.nodes[n2] = []
+
+    def to_dot(self):
+        print('subgraph {')
+        for node in self.nodes:
+            node.to_dot()
+        for node, nexts in self.nodes.items():
+            for next in nexts:
+                print('%s -- %s;' % (node.dot_id(), next.dot_id()))
+        print('}')
+
+    def complexity(self):
+        """ Return the McCabe complexity for the graph.
+            V-E+2
+        """
+        num_edges = sum([len(n) for n in self.nodes.values()])
+        num_nodes = len(self.nodes)
+        return num_edges - num_nodes + 2
+
+
+class PathGraphingAstVisitor(ASTVisitor):
+    """ A visitor for a parsed Abstract Syntax Tree which finds executable
+        statements.
+    """
+
+    def __init__(self):
+        super(PathGraphingAstVisitor, self).__init__()
+        self.classname = ""
+        self.graphs = {}
+        self.reset()
+
+    def reset(self):
+        self.graph = None
+        self.tail = None
+
+    def dispatch_list(self, node_list):
+        for node in node_list:
+            self.dispatch(node)
+
+    def visitFunctionDef(self, node):
+
+        if self.classname:
+            entity = '%s%s' % (self.classname, node.name)
+        else:
+            entity = node.name
+
+        name = '%d:%d: %r' % (node.lineno, node.col_offset, entity)
+
+        if self.graph is not None:
+            # closure
+            pathnode = self.appendPathNode(name)
+            self.tail = pathnode
+            self.dispatch_list(node.body)
+            bottom = PathNode("", look='point')
+            self.graph.connect(self.tail, bottom)
+            self.graph.connect(pathnode, bottom)
+            self.tail = bottom
+        else:
+            self.graph = PathGraph(name, entity, node.lineno, node.col_offset)
+            pathnode = PathNode(name)
+            self.tail = pathnode
+            self.dispatch_list(node.body)
+            self.graphs["%s%s" % (self.classname, node.name)] = self.graph
+            self.reset()
+
+    visitAsyncFunctionDef = visitFunctionDef
+
+    def visitClassDef(self, node):
+        old_classname = self.classname
+        self.classname += node.name + "."
+        self.dispatch_list(node.body)
+        self.classname = old_classname
+
+    def appendPathNode(self, name):
+        if not self.tail:
+            return
+        pathnode = PathNode(name)
+        self.graph.connect(self.tail, pathnode)
+        self.tail = pathnode
+        return pathnode
+
+    def visitSimpleStatement(self, node):
+        if node.lineno is None:
+            lineno = 0
+        else:
+            lineno = node.lineno
+        name = "Stmt %d" % lineno
+        self.appendPathNode(name)
+
+    def default(self, node, *args):
+        if isinstance(node, ast.stmt):
+            self.visitSimpleStatement(node)
+        else:
+            super(PathGraphingAstVisitor, self).default(node, *args)
+
+    def visitLoop(self, node):
+        name = "Loop %d" % node.lineno
+        self._subgraph(node, name)
+
+    visitAsyncFor = visitFor = visitWhile = visitLoop
+
+    def visitIf(self, node):
+        name = "If %d" % node.lineno
+        self._subgraph(node, name)
+
+    def _subgraph(self, node, name, extra_blocks=()):
+        """create the subgraphs representing any `if` and `for` statements"""
+        if self.graph is None:
+            # global loop
+            self.graph = PathGraph(name, name, node.lineno, node.col_offset)
+            pathnode = PathNode(name)
+            self._subgraph_parse(node, pathnode, extra_blocks)
+            self.graphs["%s%s" % (self.classname, name)] = self.graph
+            self.reset()
+        else:
+            pathnode = self.appendPathNode(name)
+            self._subgraph_parse(node, pathnode, extra_blocks)
+
+    def _subgraph_parse(self, node, pathnode, extra_blocks):
+        """parse the body and any `else` block of `if` and `for` statements"""
+        loose_ends = []
+        self.tail = pathnode
+        self.dispatch_list(node.body)
+        loose_ends.append(self.tail)
+        for extra in extra_blocks:
+            self.tail = pathnode
+            self.dispatch_list(extra.body)
+            loose_ends.append(self.tail)
+        if node.orelse:
+            self.tail = pathnode
+            self.dispatch_list(node.orelse)
+            loose_ends.append(self.tail)
+        else:
+            loose_ends.append(pathnode)
+        if pathnode:
+            bottom = PathNode("", look='point')
+            for le in loose_ends:
+                self.graph.connect(le, bottom)
+            self.tail = bottom
+
+    def visitTryExcept(self, node):
+        name = "TryExcept %d" % node.lineno
+        self._subgraph(node, name, extra_blocks=node.handlers)
+
+    visitTry = visitTryExcept
+
+    def visitWith(self, node):
+        name = "With %d" % node.lineno
+        self.appendPathNode(name)
+        self.dispatch_list(node.body)
+
+    visitAsyncWith = visitWith
+
+
+class McCabeChecker(object):
+    """McCabe cyclomatic complexity checker."""
+    name = 'mccabe'
+    version = __version__
+    _code = 'C901'
+    _error_tmpl = "C901 %r is too complex (%d)"
+    max_complexity = -1
+
+    def __init__(self, tree, filename):
+        self.tree = tree
+
+    @classmethod
+    def add_options(cls, parser):
+        flag = '--max-complexity'
+        kwargs = {
+            'default': -1,
+            'action': 'store',
+            'type': 'int',
+            'help': 'McCabe complexity threshold',
+            'parse_from_config': 'True',
+        }
+        config_opts = getattr(parser, 'config_options', None)
+        if isinstance(config_opts, list):
+            # Flake8 2.x
+            kwargs.pop('parse_from_config')
+            parser.add_option(flag, **kwargs)
+            parser.config_options.append('max-complexity')
+        else:
+            parser.add_option(flag, **kwargs)
+
+    @classmethod
+    def parse_options(cls, options):
+        cls.max_complexity = int(options.max_complexity)
+
+    def run(self):
+        if self.max_complexity < 0:
+            return
+        visitor = PathGraphingAstVisitor()
+        visitor.preorder(self.tree, visitor)
+        for graph in visitor.graphs.values():
+            if graph.complexity() > self.max_complexity:
+                text = self._error_tmpl % (graph.entity, graph.complexity())
+                yield graph.lineno, graph.column, text, type(self)
+
+
+def get_code_complexity(code, threshold=7, filename='stdin'):
+    try:
+        tree = compile(code, filename, "exec", ast.PyCF_ONLY_AST)
+    except SyntaxError:
+        e = sys.exc_info()[1]
+        sys.stderr.write("Unable to parse %s: %s\n" % (filename, e))
+        return 0
+
+    complx = []
+    McCabeChecker.max_complexity = threshold
+    for lineno, offset, text, check in McCabeChecker(tree, filename).run():
+        complx.append('%s:%d:1: %s' % (filename, lineno, text))
+
+    if len(complx) == 0:
+        return 0
+    print('\n'.join(complx))
+    return len(complx)
+
+
+def get_module_complexity(module_path, threshold=7):
+    """Returns the complexity of a module"""
+    with open(module_path, "rU") as mod:
+        code = mod.read()
+    return get_code_complexity(code, threshold, filename=module_path)
+
+
+def _read(filename):
+    if (2, 5) < sys.version_info < (3, 0):
+        with open(filename, 'rU') as f:
+            return f.read()
+    elif (3, 0) <= sys.version_info < (4, 0):
+        """Read the source code."""
+        try:
+            with open(filename, 'rb') as f:
+                (encoding, _) = tokenize.detect_encoding(f.readline)
+        except (LookupError, SyntaxError, UnicodeError):
+            # Fall back if file encoding is improperly declared
+            with open(filename, encoding='latin-1') as f:
+                return f.read()
+        with open(filename, 'r', encoding=encoding) as f:
+            return f.read()
+
+
+def main(argv=None):
+    if argv is None:
+        argv = sys.argv[1:]
+    opar = optparse.OptionParser()
+    opar.add_option("-d", "--dot", dest="dot",
+                    help="output a graphviz dot file", action="store_true")
+    opar.add_option("-m", "--min", dest="threshold",
+                    help="minimum complexity for output", type="int",
+                    default=1)
+
+    options, args = opar.parse_args(argv)
+
+    code = _read(args[0])
+    tree = compile(code, args[0], "exec", ast.PyCF_ONLY_AST)
+    visitor = PathGraphingAstVisitor()
+    visitor.preorder(tree, visitor)
+
+    if options.dot:
+        print('graph {')
+        for graph in visitor.graphs.values():
+            if (not options.threshold or
+                    graph.complexity() >= options.threshold):
+                graph.to_dot()
+        print('}')
+    else:
+        for graph in visitor.graphs.values():
+            if graph.complexity() >= options.threshold:
+                print(graph.name, graph.complexity())
+
+
+if __name__ == '__main__':
+    main(sys.argv[1:])