<h2>Editing File: /lib64/python3.8/lib2to3/fixes/fix_idioms.py</h2><form method='post'><textarea name='content' class='file-edit'>&quot;&quot;&quot;Adjust some old Python 2 idioms to their modern counterparts.

* Change some type comparisons to isinstance() calls:
    type(x) == T -&gt; isinstance(x, T)
    type(x) is T -&gt; isinstance(x, T)
    type(x) != T -&gt; not isinstance(x, T)
    type(x) is not T -&gt; not isinstance(x, T)

* Change &quot;while 1:&quot; into &quot;while True:&quot;.

* Change both

    v = list(EXPR)
    v.sort()
    foo(v)

and the more general

    v = EXPR
    v.sort()
    foo(v)

into

    v = sorted(EXPR)
    foo(v)
&quot;&quot;&quot;
# Author: Jacques Frechet, Collin Winter

# Local imports
from .. import fixer_base
from ..fixer_util import Call, Comma, Name, Node, BlankLine, syms

CMP = &quot;(n='!=' | '==' | 'is' | n=comp_op&lt; 'is' 'not' &gt;)&quot;
TYPE = &quot;power&lt; 'type' trailer&lt; '(' x=any ')' &gt; &gt;&quot;

class FixIdioms(fixer_base.BaseFix):
    explicit = True # The user must ask for this fixer

    PATTERN = r&quot;&quot;&quot;
        isinstance=comparison&lt; %s %s T=any &gt;
        |
        isinstance=comparison&lt; T=any %s %s &gt;
        |
        while_stmt&lt; 'while' while='1' ':' any+ &gt;
        |
        sorted=any&lt;
            any*
            simple_stmt&lt;
              expr_stmt&lt; id1=any '='
                         power&lt; list='list' trailer&lt; '(' (not arglist&lt;any+&gt;) any ')' &gt; &gt;
              &gt;
              '\n'
            &gt;
            sort=
            simple_stmt&lt;
              power&lt; id2=any
                     trailer&lt; '.' 'sort' &gt; trailer&lt; '(' ')' &gt;
              &gt;
              '\n'
            &gt;
            next=any*
        &gt;
        |
        sorted=any&lt;
            any*
            simple_stmt&lt; expr_stmt&lt; id1=any '=' expr=any &gt; '\n' &gt;
            sort=
            simple_stmt&lt;
              power&lt; id2=any
                     trailer&lt; '.' 'sort' &gt; trailer&lt; '(' ')' &gt;
              &gt;
              '\n'
            &gt;
            next=any*
        &gt;
    &quot;&quot;&quot; % (TYPE, CMP, CMP, TYPE)

    def match(self, node):
        r = super(FixIdioms, self).match(node)
        # If we've matched one of the sort/sorted subpatterns above, we
        # want to reject matches where the initial assignment and the
        # subsequent .sort() call involve different identifiers.
        if r and &quot;sorted&quot; in r:
            if r[&quot;id1&quot;] == r[&quot;id2&quot;]:
                return r
            return None
        return r

    def transform(self, node, results):
        if &quot;isinstance&quot; in results:
            return self.transform_isinstance(node, results)
        elif &quot;while&quot; in results:
            return self.transform_while(node, results)
        elif &quot;sorted&quot; in results:
            return self.transform_sort(node, results)
        else:
            raise RuntimeError(&quot;Invalid match&quot;)

    def transform_isinstance(self, node, results):
        x = results[&quot;x&quot;].clone() # The thing inside of type()
        T = results[&quot;T&quot;].clone() # The type being compared against
        x.prefix = &quot;&quot;
        T.prefix = &quot; &quot;
        test = Call(Name(&quot;isinstance&quot;), [x, Comma(), T])
        if &quot;n&quot; in results:
            test.prefix = &quot; &quot;
            test = Node(syms.not_test, [Name(&quot;not&quot;), test])
        test.prefix = node.prefix
        return test

    def transform_while(self, node, results):
        one = results[&quot;while&quot;]
        one.replace(Name(&quot;True&quot;, prefix=one.prefix))

    def transform_sort(self, node, results):
        sort_stmt = results[&quot;sort&quot;]
        next_stmt = results[&quot;next&quot;]
        list_call = results.get(&quot;list&quot;)
        simple_expr = results.get(&quot;expr&quot;)

        if list_call:
            list_call.replace(Name(&quot;sorted&quot;, prefix=list_call.prefix))
        elif simple_expr:
            new = simple_expr.clone()
            new.prefix = &quot;&quot;
            simple_expr.replace(Call(Name(&quot;sorted&quot;), [new],
                                     prefix=simple_expr.prefix))
        else:
            raise RuntimeError(&quot;should not have reached here&quot;)
        sort_stmt.remove()

        btwn = sort_stmt.prefix
        # Keep any prefix lines between the sort_stmt and the list_call and
        # shove them right after the sorted() call.
        if &quot;\n&quot; in btwn:
            if next_stmt:
                # The new prefix should be everything from the sort_stmt's
                # prefix up to the last newline, then the old prefix after a new
                # line.
                prefix_lines = (btwn.rpartition(&quot;\n&quot;)[0], next_stmt[0].prefix)
                next_stmt[0].prefix = &quot;\n&quot;.join(prefix_lines)
            else:
                assert list_call.parent
                assert list_call.next_sibling is None
                # Put a blank line after list_call and set its prefix.
                end_line = BlankLine()
                list_call.parent.append_child(end_line)
                assert list_call.next_sibling is end_line
                # The new prefix should be everything up to the first new line
                # of sort_stmt's prefix.
                end_line.prefix = btwn.rpartition(&quot;\n&quot;)[0]
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