refactor: use f-strings more

Author: nedbat

coverage/config.py

@@ -449,7 +449,7 @@ def _set_attr_from_config_option(
         """
         section, option = where.split(":")
         if cp.has_option(section, option):
-            method = getattr(cp, "get" + type_)
+            method = getattr(cp, f"get{type_}")
             setattr(self, attr, method(section, option))
             return True
         return False

coverage/context.py

@@ -6,7 +6,6 @@
 from __future__ import annotations
 
 from types import FrameType
-from typing import cast
 from collections.abc import Sequence
 
 from coverage.types import TShouldStartContextFn
@@ -65,11 +64,11 @@ def qualname_from_frame(frame: FrameType) -> str | None:
         func = frame.f_globals.get(fname)
         if func is None:
             return None
-        return cast(str, func.__module__ + "." + fname)
+        return f"{func.__module__}.{fname}"
 
     func = getattr(method, "__func__", None)
     if func is None:
         cls = self.__class__
-        return cast(str, cls.__module__ + "." + cls.__name__ + "." + fname)
+        return f"{cls.__module__}.{cls.__name__}.{fname}"
 
-    return cast(str, func.__module__ + "." + func.__qualname__)
+    return f"{func.__module__}.{func.__qualname__}"

coverage/debug.py

@@ -362,7 +362,7 @@ def filter(self, text: str) -> str:
         """Add a cwd message for each new cwd."""
         cwd = os.getcwd()
         if cwd != self.cwd:
-            text = f"cwd is now {cwd!r}\n" + text
+            text = f"cwd is now {cwd!r}\n{text}"
             self.cwd = cwd
         return text
 
@@ -404,7 +404,7 @@ def filter(self, text: str) -> str:
         """Add a message when the pytest test changes."""
         test_name = os.getenv("PYTEST_CURRENT_TEST")
         if test_name != self.test_name:
-            text = f"Pytest context: {test_name}\n" + text
+            text = f"Pytest context: {test_name}\n{text}"
             self.test_name = test_name
         return text
 

coverage/execfile.py

@@ -142,7 +142,7 @@ def _prepare2(self) -> None:
             # Running a directory means running the __main__.py file in that
             # directory.
             for ext in [".py", ".pyc", ".pyo"]:
-                try_filename = os.path.join(self.arg0, "__main__" + ext)
+                try_filename = os.path.join(self.arg0, f"__main__{ext}")
                 # 3.8.10 changed how files are reported when running a
                 # directory.
                 try_filename = os.path.abspath(try_filename)

coverage/files.py

@@ -332,7 +332,7 @@ def _glob_to_regex(pattern: str) -> str:
     # Turn all backslashes into slashes to simplify the tokenizer.
     pattern = pattern.replace("\\", "/")
     if "/" not in pattern:
-        pattern = "**/" + pattern
+        pattern = f"**/{pattern}"
     path_rx = []
     pos = 0
     while pos < len(pattern):

coverage/parser.py

@@ -741,7 +741,7 @@ def analyze(self) -> None:
         """Examine the AST tree from `self.root_node` to determine possible arcs."""
         for node in ast.walk(self.root_node):
             node_name = node.__class__.__name__
-            code_object_handler = getattr(self, "_code_object__" + node_name, None)
+            code_object_handler = getattr(self, f"_code_object__{node_name}", None)
             if code_object_handler is not None:
                 code_object_handler(node)
 
@@ -832,7 +832,7 @@ def line_for_node(self, node: ast.AST) -> TLineNo:
         node_name = node.__class__.__name__
         handler = cast(
             Optional[Callable[[ast.AST], TLineNo]],
-            getattr(self, "_line__" + node_name, None),
+            getattr(self, f"_line__{node_name}", None),
         )
         if handler is not None:
             line = handler(node)
@@ -913,7 +913,7 @@ def node_exits(self, node: ast.AST) -> set[ArcStart]:
         node_name = node.__class__.__name__
         handler = cast(
             Optional[Callable[[ast.AST], set[ArcStart]]],
-            getattr(self, "_handle__" + node_name, None),
+            getattr(self, f"_handle__{node_name}", None),
         )
         if handler is not None:
             arc_starts = handler(node)
@@ -989,7 +989,7 @@ def find_non_missing_node(self, node: ast.AST) -> ast.AST | None:
 
         missing_fn = cast(
             Optional[Callable[[ast.AST], Optional[ast.AST]]],
-            getattr(self, "_missing__" + node.__class__.__name__, None),
+            getattr(self, f"_missing__{node.__class__.__name__}", None),
         )
         if missing_fn is not None:
             ret_node = missing_fn(node)

coverage/sqldata.py

@@ -266,7 +266,7 @@ def _choose_filename(self) -> None:
             self._filename = self._basename
             suffix = filename_suffix(self._suffix)
             if suffix:
-                self._filename += "." + suffix
+                self._filename += f".{suffix}"
 
     def _reset(self) -> None:
         """Reset our attributes."""