521 lines
17 KiB
Python
521 lines
17 KiB
Python
"""
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Utility functions from 2to3, 3to2 and python-modernize (and some home-grown
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ones).
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Licences:
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2to3: PSF License v2
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3to2: Apache Software License (from 3to2/setup.py)
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python-modernize licence: BSD (from python-modernize/LICENSE)
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"""
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from lib2to3.fixer_util import (FromImport, Newline, is_import,
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find_root, does_tree_import, Comma)
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from lib2to3.pytree import Leaf, Node
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from lib2to3.pygram import python_symbols as syms, python_grammar
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from lib2to3.pygram import token
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from lib2to3.fixer_util import (Node, Call, Name, syms, Comma, Number)
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import re
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def canonical_fix_name(fix, avail_fixes):
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"""
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Examples:
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>>> canonical_fix_name('fix_wrap_text_literals')
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'libfuturize.fixes.fix_wrap_text_literals'
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>>> canonical_fix_name('wrap_text_literals')
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'libfuturize.fixes.fix_wrap_text_literals'
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>>> canonical_fix_name('wrap_te')
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ValueError("unknown fixer name")
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>>> canonical_fix_name('wrap')
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ValueError("ambiguous fixer name")
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"""
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if ".fix_" in fix:
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return fix
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else:
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if fix.startswith('fix_'):
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fix = fix[4:]
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# Infer the full module name for the fixer.
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# First ensure that no names clash (e.g.
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# lib2to3.fixes.fix_blah and libfuturize.fixes.fix_blah):
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found = [f for f in avail_fixes
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if f.endswith('fix_{0}'.format(fix))]
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if len(found) > 1:
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raise ValueError("Ambiguous fixer name. Choose a fully qualified "
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"module name instead from these:\n" +
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"\n".join(" " + myf for myf in found))
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elif len(found) == 0:
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raise ValueError("Unknown fixer. Use --list-fixes or -l for a list.")
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return found[0]
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## These functions are from 3to2 by Joe Amenta:
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def Star(prefix=None):
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return Leaf(token.STAR, u'*', prefix=prefix)
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def DoubleStar(prefix=None):
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return Leaf(token.DOUBLESTAR, u'**', prefix=prefix)
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def Minus(prefix=None):
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return Leaf(token.MINUS, u'-', prefix=prefix)
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def commatize(leafs):
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"""
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Accepts/turns: (Name, Name, ..., Name, Name)
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Returns/into: (Name, Comma, Name, Comma, ..., Name, Comma, Name)
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"""
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new_leafs = []
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for leaf in leafs:
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new_leafs.append(leaf)
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new_leafs.append(Comma())
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del new_leafs[-1]
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return new_leafs
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def indentation(node):
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"""
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Returns the indentation for this node
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Iff a node is in a suite, then it has indentation.
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"""
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while node.parent is not None and node.parent.type != syms.suite:
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node = node.parent
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if node.parent is None:
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return u""
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# The first three children of a suite are NEWLINE, INDENT, (some other node)
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# INDENT.value contains the indentation for this suite
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# anything after (some other node) has the indentation as its prefix.
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if node.type == token.INDENT:
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return node.value
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elif node.prev_sibling is not None and node.prev_sibling.type == token.INDENT:
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return node.prev_sibling.value
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elif node.prev_sibling is None:
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return u""
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else:
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return node.prefix
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def indentation_step(node):
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"""
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Dirty little trick to get the difference between each indentation level
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Implemented by finding the shortest indentation string
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(technically, the "least" of all of the indentation strings, but
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tabs and spaces mixed won't get this far, so those are synonymous.)
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"""
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r = find_root(node)
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# Collect all indentations into one set.
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all_indents = set(i.value for i in r.pre_order() if i.type == token.INDENT)
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if not all_indents:
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# nothing is indented anywhere, so we get to pick what we want
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return u" " # four spaces is a popular convention
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else:
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return min(all_indents)
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def suitify(parent):
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"""
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Turn the stuff after the first colon in parent's children
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into a suite, if it wasn't already
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"""
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for node in parent.children:
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if node.type == syms.suite:
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# already in the prefered format, do nothing
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return
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# One-liners have no suite node, we have to fake one up
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for i, node in enumerate(parent.children):
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if node.type == token.COLON:
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break
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else:
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raise ValueError(u"No class suite and no ':'!")
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# Move everything into a suite node
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suite = Node(syms.suite, [Newline(), Leaf(token.INDENT, indentation(node) + indentation_step(node))])
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one_node = parent.children[i+1]
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one_node.remove()
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one_node.prefix = u''
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suite.append_child(one_node)
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parent.append_child(suite)
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def NameImport(package, as_name=None, prefix=None):
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"""
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Accepts a package (Name node), name to import it as (string), and
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optional prefix and returns a node:
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import <package> [as <as_name>]
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"""
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if prefix is None:
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prefix = u""
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children = [Name(u"import", prefix=prefix), package]
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if as_name is not None:
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children.extend([Name(u"as", prefix=u" "),
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Name(as_name, prefix=u" ")])
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return Node(syms.import_name, children)
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_compound_stmts = (syms.if_stmt, syms.while_stmt, syms.for_stmt, syms.try_stmt, syms.with_stmt)
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_import_stmts = (syms.import_name, syms.import_from)
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def import_binding_scope(node):
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"""
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Generator yields all nodes for which a node (an import_stmt) has scope
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The purpose of this is for a call to _find() on each of them
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"""
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# import_name / import_from are small_stmts
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assert node.type in _import_stmts
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test = node.next_sibling
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# A small_stmt can only be followed by a SEMI or a NEWLINE.
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while test.type == token.SEMI:
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nxt = test.next_sibling
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# A SEMI can only be followed by a small_stmt or a NEWLINE
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if nxt.type == token.NEWLINE:
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break
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else:
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yield nxt
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# A small_stmt can only be followed by either a SEMI or a NEWLINE
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test = nxt.next_sibling
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# Covered all subsequent small_stmts after the import_stmt
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# Now to cover all subsequent stmts after the parent simple_stmt
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parent = node.parent
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assert parent.type == syms.simple_stmt
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test = parent.next_sibling
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while test is not None:
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# Yes, this will yield NEWLINE and DEDENT. Deal with it.
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yield test
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test = test.next_sibling
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context = parent.parent
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# Recursively yield nodes following imports inside of a if/while/for/try/with statement
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if context.type in _compound_stmts:
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# import is in a one-liner
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c = context
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while c.next_sibling is not None:
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yield c.next_sibling
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c = c.next_sibling
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context = context.parent
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# Can't chain one-liners on one line, so that takes care of that.
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p = context.parent
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if p is None:
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return
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# in a multi-line suite
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while p.type in _compound_stmts:
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if context.type == syms.suite:
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yield context
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context = context.next_sibling
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if context is None:
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context = p.parent
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p = context.parent
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if p is None:
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break
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def ImportAsName(name, as_name, prefix=None):
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new_name = Name(name)
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new_as = Name(u"as", prefix=u" ")
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new_as_name = Name(as_name, prefix=u" ")
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new_node = Node(syms.import_as_name, [new_name, new_as, new_as_name])
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if prefix is not None:
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new_node.prefix = prefix
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return new_node
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def is_docstring(node):
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"""
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Returns True if the node appears to be a docstring
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"""
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return (node.type == syms.simple_stmt and
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len(node.children) > 0 and node.children[0].type == token.STRING)
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def future_import(feature, node):
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"""
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This seems to work
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"""
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root = find_root(node)
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if does_tree_import(u"__future__", feature, node):
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return
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# Look for a shebang or encoding line
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shebang_encoding_idx = None
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for idx, node in enumerate(root.children):
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# Is it a shebang or encoding line?
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if is_shebang_comment(node) or is_encoding_comment(node):
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shebang_encoding_idx = idx
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if is_docstring(node):
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# skip over docstring
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continue
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names = check_future_import(node)
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if not names:
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# not a future statement; need to insert before this
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break
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if feature in names:
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# already imported
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return
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import_ = FromImport(u'__future__', [Leaf(token.NAME, feature, prefix=" ")])
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if shebang_encoding_idx == 0 and idx == 0:
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# If this __future__ import would go on the first line,
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# detach the shebang / encoding prefix from the current first line.
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# and attach it to our new __future__ import node.
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import_.prefix = root.children[0].prefix
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root.children[0].prefix = u''
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# End the __future__ import line with a newline and add a blank line
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# afterwards:
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children = [import_ , Newline()]
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root.insert_child(idx, Node(syms.simple_stmt, children))
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def future_import2(feature, node):
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"""
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An alternative to future_import() which might not work ...
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"""
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root = find_root(node)
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if does_tree_import(u"__future__", feature, node):
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return
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insert_pos = 0
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for idx, node in enumerate(root.children):
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if node.type == syms.simple_stmt and node.children and \
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node.children[0].type == token.STRING:
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insert_pos = idx + 1
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break
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for thing_after in root.children[insert_pos:]:
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if thing_after.type == token.NEWLINE:
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insert_pos += 1
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continue
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prefix = thing_after.prefix
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thing_after.prefix = u""
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break
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else:
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prefix = u""
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import_ = FromImport(u"__future__", [Leaf(token.NAME, feature, prefix=u" ")])
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children = [import_, Newline()]
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root.insert_child(insert_pos, Node(syms.simple_stmt, children, prefix=prefix))
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def parse_args(arglist, scheme):
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u"""
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Parse a list of arguments into a dict
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"""
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arglist = [i for i in arglist if i.type != token.COMMA]
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ret_mapping = dict([(k, None) for k in scheme])
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for i, arg in enumerate(arglist):
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if arg.type == syms.argument and arg.children[1].type == token.EQUAL:
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# argument < NAME '=' any >
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slot = arg.children[0].value
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ret_mapping[slot] = arg.children[2]
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else:
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slot = scheme[i]
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ret_mapping[slot] = arg
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return ret_mapping
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# def is_import_from(node):
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# """Returns true if the node is a statement "from ... import ..."
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# """
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# return node.type == syms.import_from
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def is_import_stmt(node):
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return (node.type == syms.simple_stmt and node.children and
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is_import(node.children[0]))
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def touch_import_top(package, name_to_import, node):
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"""Works like `does_tree_import` but adds an import statement at the
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top if it was not imported (but below any __future__ imports) and below any
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comments such as shebang lines).
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Based on lib2to3.fixer_util.touch_import()
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Calling this multiple times adds the imports in reverse order.
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Also adds "standard_library.install_aliases()" after "from future import
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standard_library". This should probably be factored into another function.
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"""
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root = find_root(node)
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if does_tree_import(package, name_to_import, root):
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return
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# Ideally, we would look for whether futurize --all-imports has been run,
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# as indicated by the presence of ``from builtins import (ascii, ...,
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# zip)`` -- and, if it has, we wouldn't import the name again.
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# Look for __future__ imports and insert below them
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found = False
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for name in ['absolute_import', 'division', 'print_function',
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'unicode_literals']:
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if does_tree_import('__future__', name, root):
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found = True
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break
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if found:
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# At least one __future__ import. We want to loop until we've seen them
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# all.
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start, end = None, None
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for idx, node in enumerate(root.children):
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if check_future_import(node):
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start = idx
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# Start looping
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idx2 = start
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while node:
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node = node.next_sibling
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idx2 += 1
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if not check_future_import(node):
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end = idx2
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break
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break
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assert start is not None
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assert end is not None
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insert_pos = end
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else:
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# No __future__ imports.
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# We look for a docstring and insert the new node below that. If no docstring
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# exists, just insert the node at the top.
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for idx, node in enumerate(root.children):
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if node.type != syms.simple_stmt:
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break
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if not is_docstring(node):
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# This is the usual case.
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break
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insert_pos = idx
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if package is None:
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import_ = Node(syms.import_name, [
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Leaf(token.NAME, u"import"),
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Leaf(token.NAME, name_to_import, prefix=u" ")
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])
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else:
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import_ = FromImport(package, [Leaf(token.NAME, name_to_import, prefix=u" ")])
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if name_to_import == u'standard_library':
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# Add:
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# standard_library.install_aliases()
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# after:
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# from future import standard_library
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install_hooks = Node(syms.simple_stmt,
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[Node(syms.power,
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[Leaf(token.NAME, u'standard_library'),
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Node(syms.trailer, [Leaf(token.DOT, u'.'),
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Leaf(token.NAME, u'install_aliases')]),
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Node(syms.trailer, [Leaf(token.LPAR, u'('),
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Leaf(token.RPAR, u')')])
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])
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]
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)
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children_hooks = [install_hooks, Newline()]
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else:
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children_hooks = []
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# FromImport(package, [Leaf(token.NAME, name_to_import, prefix=u" ")])
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children_import = [import_, Newline()]
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old_prefix = root.children[insert_pos].prefix
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root.children[insert_pos].prefix = u''
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root.insert_child(insert_pos, Node(syms.simple_stmt, children_import, prefix=old_prefix))
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if len(children_hooks) > 0:
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root.insert_child(insert_pos + 1, Node(syms.simple_stmt, children_hooks))
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## The following functions are from python-modernize by Armin Ronacher:
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# (a little edited).
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def check_future_import(node):
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"""If this is a future import, return set of symbols that are imported,
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else return None."""
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# node should be the import statement here
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savenode = node
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if not (node.type == syms.simple_stmt and node.children):
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return set()
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node = node.children[0]
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# now node is the import_from node
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if not (node.type == syms.import_from and
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# node.type == token.NAME and # seems to break it
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hasattr(node.children[1], 'value') and
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node.children[1].value == u'__future__'):
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return set()
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if node.children[3].type == token.LPAR:
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node = node.children[4]
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else:
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node = node.children[3]
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# now node is the import_as_name[s]
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# print(python_grammar.number2symbol[node.type]) # breaks sometimes
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if node.type == syms.import_as_names:
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result = set()
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for n in node.children:
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if n.type == token.NAME:
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result.add(n.value)
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elif n.type == syms.import_as_name:
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n = n.children[0]
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assert n.type == token.NAME
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result.add(n.value)
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return result
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elif node.type == syms.import_as_name:
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node = node.children[0]
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assert node.type == token.NAME
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return set([node.value])
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elif node.type == token.NAME:
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return set([node.value])
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else:
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# TODO: handle brackets like this:
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# from __future__ import (absolute_import, division)
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assert False, "strange import: %s" % savenode
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SHEBANG_REGEX = r'^#!.*python'
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ENCODING_REGEX = r"^#.*coding[:=]\s*([-\w.]+)"
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def is_shebang_comment(node):
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"""
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Comments are prefixes for Leaf nodes. Returns whether the given node has a
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prefix that looks like a shebang line or an encoding line:
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#!/usr/bin/env python
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#!/usr/bin/python3
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"""
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return bool(re.match(SHEBANG_REGEX, node.prefix))
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def is_encoding_comment(node):
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"""
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Comments are prefixes for Leaf nodes. Returns whether the given node has a
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prefix that looks like an encoding line:
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# coding: utf-8
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# encoding: utf-8
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# -*- coding: <encoding name> -*-
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# vim: set fileencoding=<encoding name> :
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"""
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return bool(re.match(ENCODING_REGEX, node.prefix))
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def wrap_in_fn_call(fn_name, args, prefix=None):
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"""
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Example:
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>>> wrap_in_fn_call("oldstr", (arg,))
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oldstr(arg)
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>>> wrap_in_fn_call("olddiv", (arg1, arg2))
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olddiv(arg1, arg2)
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>>> wrap_in_fn_call("olddiv", [arg1, comma, arg2, comma, arg3])
|
|
olddiv(arg1, arg2, arg3)
|
|
"""
|
|
assert len(args) > 0
|
|
if len(args) == 2:
|
|
expr1, expr2 = args
|
|
newargs = [expr1, Comma(), expr2]
|
|
else:
|
|
newargs = args
|
|
return Call(Name(fn_name), newargs, prefix=prefix)
|