Convert legacy string formatting to f-strings (#4685)

* the changes

* Update driver.py

scripts/migrate-black.py

@@ -77,7 +77,7 @@ def blackify(base_branch: str, black_command: str, logger: logging.Logger) -> in
         git("commit", "--allow-empty", "-aqC", commit)
 
     for commit in commits:
-        git("branch", "-qD", "%s-black" % commit)
+        git("branch", "-qD", f"{commit}-black")
 
     return 0
 

src/blib2to3/pgen2/literals.py

@@ -28,16 +28,16 @@ def escape(m: re.Match[str]) -> str:
     if tail.startswith("x"):
         hexes = tail[1:]
         if len(hexes) < 2:
-            raise ValueError("invalid hex string escape ('\\%s')" % tail)
+            raise ValueError(f"invalid hex string escape ('\\{tail}')")
         try:
             i = int(hexes, 16)
         except ValueError:
-            raise ValueError("invalid hex string escape ('\\%s')" % tail) from None
+            raise ValueError(f"invalid hex string escape ('\\{tail}')") from None
     else:
         try:
             i = int(tail, 8)
         except ValueError:
-            raise ValueError("invalid octal string escape ('\\%s')" % tail) from None
+            raise ValueError(f"invalid octal string escape ('\\{tail}')") from None
     return chr(i)
 
 

src/blib2to3/pgen2/pgen.py

@@ -140,7 +140,7 @@ def calcfirst(self, name: str) -> None:
                 if label in self.first:
                     fset = self.first[label]
                     if fset is None:
-                        raise ValueError("recursion for rule %r" % name)
+                        raise ValueError(f"recursion for rule {name!r}")
                 else:
                     self.calcfirst(label)
                     fset = self.first[label]
@@ -155,8 +155,8 @@ def calcfirst(self, name: str) -> None:
             for symbol in itsfirst:
                 if symbol in inverse:
                     raise ValueError(
-                        "rule %s is ambiguous; %s is in the first sets of %s as well"
+                        f"rule {name} is ambiguous; {symbol} is in the first sets of"
-                        " as %s" % (name, symbol, label, inverse[symbol])
+                        f" {label} as well as {inverse[symbol]}"
                     )
                 inverse[symbol] = label
         self.first[name] = totalset
@@ -237,16 +237,16 @@ def dump_nfa(self, name: str, start: "NFAState", finish: "NFAState") -> None:
                     j = len(todo)
                     todo.append(next)
                 if label is None:
-                    print("    -> %d" % j)
+                    print(f"    -> {j}")
                 else:
-                    print("    %s -> %d" % (label, j))
+                    print(f"    {label} -> {j}")
 
     def dump_dfa(self, name: str, dfa: Sequence["DFAState"]) -> None:
         print("Dump of DFA for", name)
         for i, state in enumerate(dfa):
             print("  State", i, state.isfinal and "(final)" or "")
             for label, next in sorted(state.arcs.items()):
-                print("    %s -> %d" % (label, dfa.index(next)))
+                print(f"    {label} -> {dfa.index(next)}")
 
     def simplify_dfa(self, dfa: list["DFAState"]) -> None:
         # This is not theoretically optimal, but works well enough.
@@ -330,15 +330,12 @@ def parse_atom(self) -> tuple["NFAState", "NFAState"]:
             return a, z
         else:
             self.raise_error(
-                "expected (...) or NAME or STRING, got %s/%s", self.type, self.value
+                f"expected (...) or NAME or STRING, got {self.type}/{self.value}"
             )
-            raise AssertionError
 
     def expect(self, type: int, value: Optional[Any] = None) -> str:
         if self.type != type or (value is not None and self.value != value):
-            self.raise_error(
+            self.raise_error(f"expected {type}/{value}, got {self.type}/{self.value}")
-                "expected %s/%s, got %s/%s", type, value, self.type, self.value
-            )
         value = self.value
         self.gettoken()
         return value
@@ -350,12 +347,7 @@ def gettoken(self) -> None:
         self.type, self.value, self.begin, self.end, self.line = tup
         # print token.tok_name[self.type], repr(self.value)
 
-    def raise_error(self, msg: str, *args: Any) -> NoReturn:
+    def raise_error(self, msg: str) -> NoReturn:
-        if args:
-            try:
-                msg = msg % args
-            except Exception:
-                msg = " ".join([msg] + list(map(str, args)))
         raise SyntaxError(
             msg, (str(self.filename), self.end[0], self.end[1], self.line)
         )

src/blib2to3/pgen2/tokenize.py

@@ -206,9 +206,7 @@ def printtoken(
 ) -> None:  # for testing
     (srow, scol) = srow_col
     (erow, ecol) = erow_col
-    print(
+    print(f"{srow},{scol}-{erow},{ecol}:\t{tok_name[type]}\t{token!r}")
-        "%d,%d-%d,%d:\t%s\t%s" % (srow, scol, erow, ecol, tok_name[type], repr(token))
-    )
 
 
 if __name__ == "__main__":  # testing

src/blib2to3/pytree.py

@@ -268,11 +268,7 @@ def __init__(
     def __repr__(self) -> str:
         """Return a canonical string representation."""
         assert self.type is not None
-        return "{}({}, {!r})".format(
+        return f"{self.__class__.__name__}({type_repr(self.type)}, {self.children!r})"
-            self.__class__.__name__,
-            type_repr(self.type),
-            self.children,
-        )
 
     def __str__(self) -> str:
         """
@@ -421,10 +417,9 @@ def __repr__(self) -> str:
         from .pgen2.token import tok_name
 
         assert self.type is not None
-        return "{}({}, {!r})".format(
+        return (
-            self.__class__.__name__,
+            f"{self.__class__.__name__}({tok_name.get(self.type, self.type)},"
-            tok_name.get(self.type, self.type),
+            f" {self.value!r})"
-            self.value,
         )
 
     def __str__(self) -> str:
@@ -527,7 +522,7 @@ def __repr__(self) -> str:
         args = [type_repr(self.type), self.content, self.name]
         while args and args[-1] is None:
             del args[-1]
-        return "{}({})".format(self.__class__.__name__, ", ".join(map(repr, args)))
+        return f"{self.__class__.__name__}({', '.join(map(repr, args))})"
 
     def _submatch(self, node, results=None) -> bool:
         raise NotImplementedError