Fix new mypy error in blib2to3 (#3674)

See python/mypy#15174

diff --git a/src/blib2to3/pgen2/tokenize.py b/src/blib2to3/pgen2/tokenize.py
index a6353d154c93d99290d2520966e0ce680d19d1bd..82ac5130badd92724779136362bdb235a37bf757 100644 (file)
--- a/src/blib2to3/pgen2/tokenize.py
+++ b/src/blib2to3/pgen2/tokenize.py
@@ -163,7 +163,6 @@ endprogs: Final = {
     '"""': double3prog,
     **{f"{prefix}'''": single3prog for prefix in _strprefixes},
     **{f'{prefix}"""': double3prog for prefix in _strprefixes},
-    **{prefix: None for prefix in _strprefixes},
 }
 
 triple_quoted: Final = (
@@ -599,11 +598,13 @@ def generate_tokens(
                 ):
                     if token[-1] == "\n":  # continued string
                         strstart = (lnum, start)
-                        endprog = (
-                            endprogs[initial]
-                            or endprogs[token[1]]
-                            or endprogs[token[2]]
+                        maybe_endprog = (
+                            endprogs.get(initial)
+                            or endprogs.get(token[1])
+                            or endprogs.get(token[2])
                         )
+                        assert maybe_endprog is not None, f"endprog not found for {token}"
+                        endprog = maybe_endprog
                         contstr, needcont = line[start:], 1
                         contline = line
                         break

diff --git a/tests/data/simple_cases/fstring.py b/tests/data/simple_cases/fstring.py
index 4b33231c01c08701c1f2fa47de9cfe8a1f0388c9..60560309376351e79d53d505dd3f89b1745eae7b 100644 (file)
--- a/tests/data/simple_cases/fstring.py
+++ b/tests/data/simple_cases/fstring.py
@@ -7,6 +7,8 @@ f"{f'''{'nested'} inner'''} outer"
 f"\"{f'{nested} inner'}\" outer"
 f"space between opening braces: { {a for a in (1, 2, 3)}}"
 f'Hello \'{tricky + "example"}\''
+f"Tried directories {str(rootdirs)} \
+but none started with prefix {parentdir_prefix}"
 
 # output
 
@@ -19,3 +21,5 @@ f"{f'''{'nested'} inner'''} outer"
 f"\"{f'{nested} inner'}\" outer"
 f"space between opening braces: { {a for a in (1, 2, 3)}}"
 f'Hello \'{tricky + "example"}\''
+f"Tried directories {str(rootdirs)} \
+but none started with prefix {parentdir_prefix}"