More f-strings, less format()

xarray/backends/common.py

@@ -560,11 +560,10 @@ def _infer_dtype(array, name=None):
 
     native_dtypes = set(np.vectorize(type, otypes=[object])(array.ravel()))
     if len(native_dtypes) > 1 and native_dtypes != {bytes, str}:
+        native_dtype_names = ", ".join(x.__name__ for x in native_dtypes)
         raise ValueError(
-            "unable to infer dtype on variable {!r}; object array "
-            "contains mixed native types: {}".format(
-                name, ", ".join(x.__name__ for x in native_dtypes)
-            )
+            f"unable to infer dtype on variable {name!r}; object array "
+            f"contains mixed native types: {native_dtype_names}"
         )
 
     element = array[(0,) * array.ndim]

xarray/computation/apply_ufunc.py

@@ -141,8 +141,13 @@ def __repr__(self):
         return f"{type(self).__name__}({list(self.input_core_dims)!r}, {list(self.output_core_dims)!r})"
 
     def __str__(self):
-        lhs = ",".join("({})".format(",".join(dims)) for dims in self.input_core_dims)
-        rhs = ",".join("({})".format(",".join(dims)) for dims in self.output_core_dims)
+        comma_separated = ",".join
+        lhs = comma_separated(
+            f"({comma_separated(dims)})" for dims in self.input_core_dims
+        )
+        rhs = comma_separated(
+            f"({comma_separated(dims)})" for dims in self.output_core_dims
+        )
         return f"{lhs}->{rhs}"
 
     def to_gufunc_string(self, exclude_dims=frozenset()):

xarray/computation/rolling.py

@@ -132,7 +132,7 @@ def __repr__(self) -> str:
         """provide a nice str repr of our rolling object"""
 
         attrs = ",".join(
-            "{k}->{v}{c}".format(k=k, v=w, c="(center)" if c else "")
+            f"{k}->{w}{'(center)' if c else ''}"
             for k, w, c in zip(self.dim, self.window, self.center, strict=True)
         )
         return f"{self.__class__.__name__} [{attrs}]"

xarray/core/formatting.py

@@ -340,17 +340,17 @@ def summarize_variable(
         first_col = pretty_print(first_col, col_width)
 
     if variable.dims:
-        dims_str = "({}) ".format(", ".join(map(str, variable.dims)))
+        dims_str = ", ".join(map(str, variable.dims))
+        dims_str = f"({dims_str}) "
     else:
         dims_str = ""
 
-    nbytes_str = f" {render_human_readable_nbytes(variable.nbytes)}"
-    front_str = f"{first_col}{dims_str}{variable.dtype}{nbytes_str} "
+    front_str = f"{first_col}{dims_str}{variable.dtype} {render_human_readable_nbytes(variable.nbytes)} "
 
     values_width = max_width - len(front_str)
     values_str = inline_variable_array_repr(variable, values_width)
 
-    return front_str + values_str
+    return f"{front_str}{values_str}"
 
 
 def summarize_attr(key, value, col_width=None):