1r"""Fixer for unicode.
2
3* Changes unicode to str and unichr to chr.
4
5* If "...\u..." is not unicode literal change it into "...\\u...".
6
7* Change u"..." into "...".
8
9"""
10
11from ..pgen2 import token
12from .. import fixer_base
13
14_mapping = {"unichr" : "chr", "unicode" : "str"}
15
16class FixUnicode(fixer_base.BaseFix):
17    BM_compatible = True
18    PATTERN = "STRING | 'unicode' | 'unichr'"
19
20    def start_tree(self, tree, filename):
21        super(FixUnicode, self).start_tree(tree, filename)
22        self.unicode_literals = 'unicode_literals' in tree.future_features
23
24    def transform(self, node, results):
25        if node.type == token.NAME:
26            new = node.clone()
27            new.value = _mapping[node.value]
28            return new
29        elif node.type == token.STRING:
30            val = node.value
31            if not self.unicode_literals and val[0] in '\'"' and '\\' in val:
32                val = r'\\'.join([
33                    v.replace('\\u', r'\\u').replace('\\U', r'\\U')
34                    for v in val.split(r'\\')
35                ])
36            if val[0] in 'uU':
37                val = val[1:]
38            if val == node.value:
39                return node
40            new = node.clone()
41            new.value = val
42            return new
43