Python fixer_util.FromImport类代码示例

 def test_is_shebang_comment(self):
     """
     Tests whether the libfuturize.fixer_util.is_shebang_comment() function is working
     """
     node = FromImport(u'math', [Leaf(token.NAME, u'cos', prefix=" ")])
     node.prefix = u'#!/usr/bin/env python\n'
     self.assertTrue(is_shebang_comment(node))

    def transform(self, node, results):
        imp = results.get('imp')

        if node.type == syms.import_from:
            # Some imps are top-level (e.g., 'import ham')
            # some are first level (e.g., 'import ham.eggs')
            # some are third level (e.g., 'import ham.eggs as spam')
            # Hence, the loop
            while not hasattr(imp, 'value'):
                imp = imp.children[0]
            if imp.value.startswith("ui_"):
                imp.value = u"." + imp.value
                imp.changed()
        else:
            first = imp
            if isinstance(imp, Node):
                first = next(imp.leaves())

            if not isinstance(first, Leaf):
                return

            if not first.value.startswith("ui_"):
                return

            new = FromImport(".", [imp])
            new.prefix = node.prefix
            return new

    def transform(self, node, results):
        if self.skip:
            return
        imp = results['imp']

        if node.type == syms.import_from:
            # Some imps are top-level (eg: 'import ham')
            # some are first level (eg: 'import ham.eggs')
            # some are third level (eg: 'import ham.eggs as spam')
            # Hence, the loop
            while not hasattr(imp, 'value'):
                imp = imp.children[0]
            if self.probably_a_local_import(imp.value):
                imp.value = "." + imp.value
                imp.changed()
        else:
            have_local = False
            have_absolute = False
            for mod_name in traverse_imports(imp):
                if self.probably_a_local_import(mod_name):
                    have_local = True
                else:
                    have_absolute = True
            if have_absolute:
                if have_local:
                    # We won't handle both sibling and absolute imports in the
                    # same statement at the moment.
                    self.warning(node, "absolute and local imports together")
                return

            new = FromImport(".", [imp])
            new.prefix = node.prefix
            return new

 def new_future_import(self, old):
     new = FromImport("__future__",
                      [Name("absolute_import", prefix=" "), Comma(),
                       Name("division", prefix=" "), Comma(),
                       Name("print_function", prefix=" ")])
     if old is not None:
         new.prefix = old.prefix
     return new

    def test_is_shebang_comment(self):
        """
        Tests whether the fixer_util.is_encoding_comment() function is working.
        """
        shebang_comments = [u"#!/usr/bin/env python\n" u"#!/usr/bin/python2\n", u"#! /usr/bin/python3\n"]
        not_shebang_comments = [u"# I saw a giant python\n", u"# I have never seen a python2\n"]
        for comment in shebang_comments:
            node = FromImport(u"math", [Leaf(token.NAME, u"cos", prefix=" ")])
            node.prefix = comment
            self.assertTrue(is_shebang_comment(node))

        for comment in not_shebang_comments:
            node = FromImport(u"math", [Leaf(token.NAME, u"cos", prefix=" ")])
            node.prefix = comment
            self.assertFalse(is_shebang_comment(node))

    def test_is_encoding_comment(self):
        """
        Tests whether the fixer_util.is_encoding_comment() function is working.
        """
        encoding_comments = [
            u"# coding: utf-8",
            u"# encoding: utf-8",
            u"# -*- coding: latin-1 -*-",
            u"# vim: set fileencoding=iso-8859-15 :",
        ]
        not_encoding_comments = [u"# We use the file encoding utf-8", u"coding = 'utf-8'", u"encoding = 'utf-8'"]
        for comment in encoding_comments:
            node = FromImport(u"math", [Leaf(token.NAME, u"cos", prefix=" ")])
            node.prefix = comment
            self.assertTrue(is_encoding_comment(node))

        for comment in not_encoding_comments:
            node = FromImport(u"math", [Leaf(token.NAME, u"cos", prefix=" ")])
            node.prefix = comment
            self.assertFalse(is_encoding_comment(node))

    def transform(self, node, results):
        """
        Copied from FixImport.transform(), but with this line added in
        any modules that had implicit relative imports changed:

            from __future__ import absolute_import"
        """
        if self.skip:
            return
        imp = results['imp']

        if node.type == syms.import_from:
            # Some imps are top-level (eg: 'import ham')
            # some are first level (eg: 'import ham.eggs')
            # some are third level (eg: 'import ham.eggs as spam')
            # Hence, the loop
            while not hasattr(imp, 'value'):
                imp = imp.children[0]
            if self.probably_a_local_import(imp.value):
                imp.value = u"." + imp.value
                imp.changed()
                future_import(u"absolute_import", node)
        else:
            have_local = False
            have_absolute = False
            for mod_name in traverse_imports(imp):
                if self.probably_a_local_import(mod_name):
                    have_local = True
                else:
                    have_absolute = True
            if have_absolute:
                if have_local:
                    # We won't handle both sibling and absolute imports in the
                    # same statement at the moment.
                    self.warning(node, "absolute and local imports together")
                return

            new = FromImport(u".", [imp])
            new.prefix = node.prefix
            future_import(u"absolute_import", node)
            return new

def future_import(feature, node):
    """
    This seems to work
    """
    root = find_root(node)

    if does_tree_import(u"__future__", feature, node):
        return

    # Look for a shebang or encoding line
    shebang_encoding_idx = None

    for idx, node in enumerate(root.children):
        # Is it a shebang or encoding line?
        if is_shebang_comment(node) or is_encoding_comment(node):
            shebang_encoding_idx = idx
        if node.type == syms.simple_stmt and \
           len(node.children) > 0 and node.children[0].type == token.STRING:
            # skip over docstring
            continue
        names = check_future_import(node)
        if not names:
            # not a future statement; need to insert before this
            break
        if feature in names:
            # already imported
            return

    import_ = FromImport(u'__future__', [Leaf(token.NAME, feature, prefix=" ")])
    if shebang_encoding_idx == 0 and idx == 0:
        # If this __future__ import would go on the first line,
        # detach the shebang / encoding prefix from the current first line.
        # and attach it to our new __future__ import node.
        import_.prefix = root.children[0].prefix
        root.children[0].prefix = u''
        # End the __future__ import line with a newline and add a blank line
        # afterwards:
    children = [import_ , Newline()]
    root.insert_child(idx, Node(syms.simple_stmt, children))

    def transform_member(self, node, results):
        """Transform for imports of specific module elements. Replaces
           the module to be imported from with the appropriate new
           module.
        """
        mod_member = results.get('mod_member')
        pref = mod_member.prefix
        member = results.get('member')
        if member:
            if isinstance(member, list):
                member = member[0]
            new_name = None
            for change in MAPPING[mod_member.value]:
                if member.value in change[1]:
                    new_name = change[0]
                    break

            if new_name:
                mod_member.replace(Name(new_name, prefix=pref))
            else:
                self.cannot_convert(node, 'This is an invalid module element')
        else:
            modules = []
            mod_dict = {}
            members = results['members']
            for member in members:
                if member.type == syms.import_as_name:
                    as_name = member.children[2].value
                    member_name = member.children[0].value
                else:
                    member_name = member.value
                    as_name = None
                if member_name != u',':
                    for change in MAPPING[mod_member.value]:
                        if member_name in change[1]:
                            if change[0] not in mod_dict:
                                modules.append(change[0])
                            mod_dict.setdefault(change[0], []).append(member)

            new_nodes = []
            indentation = find_indentation(node)
            first = True

            def handle_name(name, prefix):
                if name.type == syms.import_as_name:
                    kids = [Name(name.children[0].value, prefix=prefix), name.children[1].clone(), name.children[2].clone()]
                    return [Node(syms.import_as_name, kids)]
                return [Name(name.value, prefix=prefix)]

            for module in modules:
                elts = mod_dict[module]
                names = []
                for elt in elts[:-1]:
                    names.extend(handle_name(elt, pref))
                    names.append(Comma())

                names.extend(handle_name(elts[-1], pref))
                new = FromImport(module, names)
                if not first or node.parent.prefix.endswith(indentation):
                    new.prefix = indentation
                new_nodes.append(new)
                first = False

            if new_nodes:
                nodes = []
                for new_node in new_nodes[:-1]:
                    nodes.extend([new_node, Newline()])

                nodes.append(new_nodes[-1])
                node.replace(nodes)
            else:
                self.cannot_convert(node, 'All module elements are invalid')
        return

    def transform_member(self, node, results):
        """Transform for imports of specific module elements. Replaces
           the module to be imported from with the appropriate new
           module.
        """
        mod_member = results.get("mod_member")
        pref = mod_member.prefix
        member = results.get("member")

        # Simple case with only a single member being imported
        if member:
            # this may be a list of length one, or just a node
            if isinstance(member, list):
                member = member[0]
            new_name = None
            for change in MAPPING[mod_member.value]:
                if member.value in change[1]:
                    new_name = change[0]
                    break
            if new_name:
                mod_member.replace(Name(new_name, prefix=pref))
            else:
                self.cannot_convert(node, "This is an invalid module element")

        # Multiple members being imported
        else:
            # a dictionary for replacements, order matters
            modules = []
            mod_dict = {}
            members = results["members"]
            for member in members:
                # we only care about the actual members
                if member.type == syms.import_as_name:
                    as_name = member.children[2].value
                    member_name = member.children[0].value
                else:
                    member_name = member.value
                    as_name = None
                if member_name != ",":
                    for change in MAPPING[mod_member.value]:
                        if member_name in change[1]:
                            if change[0] not in mod_dict:
                                modules.append(change[0])
                            mod_dict.setdefault(change[0], []).append(member)

            new_nodes = []
            indentation = find_indentation(node)
            first = True
            def handle_name(name, prefix):
                if name.type == syms.import_as_name:
                    kids = [Name(name.children[0].value, prefix=prefix),
                            name.children[1].clone(),
                            name.children[2].clone()]
                    return [Node(syms.import_as_name, kids)]
                return [Name(name.value, prefix=prefix)]
            for module in modules:
                elts = mod_dict[module]
                names = []
                for elt in elts[:-1]:
                    names.extend(handle_name(elt, pref))
                    names.append(Comma())
                names.extend(handle_name(elts[-1], pref))
                new = FromImport(module, names)
                if not first or node.parent.prefix.endswith(indentation):
                    new.prefix = indentation
                new_nodes.append(new)
                first = False
            if new_nodes:
                nodes = []
                for new_node in new_nodes[:-1]:
                    nodes.extend([new_node, Newline()])
                nodes.append(new_nodes[-1])
                node.replace(nodes)
            else:
                self.cannot_convert(node, "All module elements are invalid")