CLN: use f-strings where possible

Mechanically transformed with `flynt -tc -a -v`

Author: akx

pandas/_config/config.py

@@ -499,7 +499,7 @@ def register_option(
     path = key.split(".")
 
     for k in path:
-        if not re.match("^" + tokenize.Name + "$", k):
+        if not re.match(f"^{tokenize.Name}$", k):
             raise ValueError(f"{k} is not a valid identifier")
         if keyword.iskeyword(k):
             raise ValueError(f"{k} is a python keyword")
@@ -707,7 +707,7 @@ def pp_options_list(keys: Iterable[str], width: int = 80, _print: bool = False):
     from textwrap import wrap
 
     def pp(name: str, ks: Iterable[str]) -> list[str]:
-        pfx = "- " + name + ".[" if name else ""
+        pfx = f"- {name}.[" if name else ""
         ls = wrap(
             ", ".join(ks),
             width,
@@ -716,7 +716,7 @@ def pp(name: str, ks: Iterable[str]) -> list[str]:
             break_long_words=False,
         )
         if ls and ls[-1] and name:
-            ls[-1] = ls[-1] + "]"
+            ls[-1] = f"{ls[-1]}]"
         return ls
 
     ls: list[str] = []

pandas/conftest.py

@@ -1773,7 +1773,7 @@ def spmatrix(request):
     """
     from scipy import sparse
 
-    return getattr(sparse, request.param + "_matrix")
+    return getattr(sparse, f"{request.param}_matrix")
 
 
 @pytest.fixture(

pandas/core/arraylike.py

@@ -304,8 +304,7 @@ def array_ufunc(self, ufunc: np.ufunc, method: str, *inputs: Any, **kwargs: Any)
             # well. Previously this raised an internal ValueError. We might
             # support it someday, so raise a NotImplementedError.
             raise NotImplementedError(
-                "Cannot apply ufunc {} to mixed DataFrame and Series "
-                "inputs.".format(ufunc)
+                f"Cannot apply ufunc {ufunc} to mixed DataFrame and Series inputs."
             )
         axes = self.axes
         for obj in alignable[1:]:

pandas/core/arrays/categorical.py

@@ -2166,7 +2166,7 @@ def _repr_categories_info(self) -> str:
         start = True
         cur_col_len = len(levheader)  # header
         sep_len, sep = (3, " < ") if self.ordered else (2, ", ")
-        linesep = sep.rstrip() + "\n"  # remove whitespace
+        linesep = f"{sep.rstrip()}\n"  # remove whitespace
         for val in category_strs:
             if max_width != 0 and cur_col_len + sep_len + len(val) > max_width:
                 levstring += linesep + (" " * (len(levheader) + 1))
@@ -2177,7 +2177,7 @@ def _repr_categories_info(self) -> str:
             levstring += val
             start = False
         # replace to simple save space by
-        return levheader + "[" + levstring.replace(" < ... < ", " ... ") + "]"
+        return f"{levheader}[{levstring.replace(' < ... < ', ' ... ')}]"
 
     def _repr_footer(self) -> str:
         info = self._repr_categories_info()

pandas/core/arrays/masked.py

@@ -1058,7 +1058,7 @@ def _reduce(self, name: str, *, skipna: bool = True, **kwargs):
             data = self.to_numpy("float64", na_value=np.nan)
 
         # median, var, std, skew, kurt, idxmin, idxmax
-        op = getattr(nanops, "nan" + name)
+        op = getattr(nanops, f"nan{name}")
         result = op(data, axis=0, skipna=skipna, mask=mask, **kwargs)
 
         if np.isnan(result):

pandas/core/arrays/string_arrow.py

@@ -317,11 +317,11 @@ def _str_contains(
         return result
 
     def _str_startswith(self, pat: str, na=None):
-        pat = "^" + re.escape(pat)
+        pat = f"^{re.escape(pat)}"
         return self._str_contains(pat, na=na, regex=True)
 
     def _str_endswith(self, pat: str, na=None):
-        pat = re.escape(pat) + "$"
+        pat = f"{re.escape(pat)}$"
         return self._str_contains(pat, na=na, regex=True)
 
     def _str_replace(
@@ -345,14 +345,14 @@ def _str_match(
         self, pat: str, case: bool = True, flags: int = 0, na: Scalar | None = None
     ):
         if not pat.startswith("^"):
-            pat = "^" + pat
+            pat = f"^{pat}"
         return self._str_contains(pat, case, flags, na, regex=True)
 
     def _str_fullmatch(
         self, pat, case: bool = True, flags: int = 0, na: Scalar | None = None
     ):
         if not pat.endswith("$") or pat.endswith("//$"):
-            pat = pat + "$"
+            pat = f"{pat}$"
         return self._str_match(pat, case, flags, na)
 
     def _str_isalnum(self):

pandas/core/computation/expr.py

@@ -410,7 +410,7 @@ def visit(self, node, **kwargs):
                     e.msg = "Python keyword not valid identifier in numexpr query"
                 raise e
 
-        method = "visit_" + type(node).__name__
+        method = f"visit_{type(node).__name__}"
         visitor = getattr(self, method)
         return visitor(node, **kwargs)
 

pandas/core/computation/parsing.py

@@ -59,7 +59,7 @@ def create_valid_python_identifier(name: str) -> str:
     )
 
     name = "".join([special_characters_replacements.get(char, char) for char in name])
-    name = "BACKTICK_QUOTED_STRING_" + name
+    name = f"BACKTICK_QUOTED_STRING_{name}"
 
     if not name.isidentifier():
         raise SyntaxError(f"Could not convert '{name}' to a valid Python identifier.")

pandas/core/computation/scope.py

@@ -250,7 +250,7 @@ def _get_vars(self, stack, scopes: list[str]) -> None:
         variables = itertools.product(scopes, stack)
         for scope, (frame, _, _, _, _, _) in variables:
             try:
-                d = getattr(frame, "f_" + scope)
+                d = getattr(frame, f"f_{scope}")
                 self.scope = DeepChainMap(self.scope.new_child(d))
             finally:
                 # won't remove it, but DECREF it

pandas/core/dtypes/dtypes.py

@@ -804,7 +804,7 @@ def __hash__(self) -> int:
     def __eq__(self, other: Any) -> bool:
         if isinstance(other, str):
             if other.startswith("M8["):
-                other = "datetime64[" + other[3:]
+                other = f"datetime64[{other[3:]}"
             return other == self.name
 
         return (

pandas/core/frame.py

@@ -1078,7 +1078,7 @@ def _repr_html_(self) -> str | None:
             # need to escape the <class>, should be the first line.
             val = buf.getvalue().replace("<", r"&lt;", 1)
             val = val.replace(">", r"&gt;", 1)
-            return "<pre>" + val + "</pre>"
+            return f"<pre>{val}</pre>"
 
         if get_option("display.notebook_repr_html"):
             max_rows = get_option("display.max_rows")

pandas/core/groupby/groupby.py

@@ -1531,9 +1531,9 @@ def f(g):
                     with np.errstate(all="ignore"):
                         return func(g, *args, **kwargs)
 
-            elif hasattr(nanops, "nan" + func):
+            elif hasattr(nanops, f"nan{func}"):
                 # TODO: should we wrap this in to e.g. _is_builtin_func?
-                f = getattr(nanops, "nan" + func)
+                f = getattr(nanops, f"nan{func}")
 
             else:
                 raise ValueError(

pandas/core/indexes/category.py

@@ -349,7 +349,7 @@ def _format_attrs(self):
         attrs = [
             (
                 "categories",
-                "[" + ", ".join(self._data._repr_categories()) + "]",
+                f"[{', '.join(self._data._repr_categories())}]",
             ),
             ("ordered", self.ordered),
         ]

pandas/core/indexes/interval.py

@@ -831,7 +831,7 @@ def _format_native_types(
     def _format_data(self, name=None) -> str:
         # TODO: integrate with categorical and make generic
         # name argument is unused here; just for compat with base / categorical
-        return self._data._format_data() + "," + self._format_space()
+        return f"{self._data._format_data()},{self._format_space()}"
 
     # --------------------------------------------------------------------
     # Set Operations

pandas/core/interchange/column.py

@@ -329,7 +329,7 @@ def _get_validity_buffer(self) -> tuple[PandasBuffer, Any]:
             return buffer, dtype
 
         try:
-            msg = _NO_VALIDITY_BUFFER[null] + " so does not have a separate mask"
+            msg = f"{_NO_VALIDITY_BUFFER[null]} so does not have a separate mask"
         except KeyError:
             # TODO: implement for other bit/byte masks?
             raise NotImplementedError("See self.describe_null")

pandas/core/nanops.py

@@ -1043,7 +1043,7 @@ def nansem(
 
 
 def _nanminmax(meth, fill_value_typ):
-    @bottleneck_switch(name="nan" + meth)
+    @bottleneck_switch(name=f"nan{meth}")
     @_datetimelike_compat
     def reduction(
         values: np.ndarray,

pandas/core/ops/docstrings.py

@@ -25,11 +25,11 @@ def make_flex_doc(op_name: str, typ: str) -> str:
     op_desc_op = op_desc["op"]
     assert op_desc_op is not None  # for mypy
     if op_name.startswith("r"):
-        equiv = "other " + op_desc_op + " " + typ
+        equiv = f"other {op_desc_op} {typ}"
     elif op_name == "divmod":
         equiv = f"{op_name}({typ}, other)"
     else:
-        equiv = typ + " " + op_desc_op + " other"
+        equiv = f"{typ} {op_desc_op} other"
 
     if typ == "series":
         base_doc = _flex_doc_SERIES

pandas/io/clipboard/__init__.py

@@ -312,7 +312,7 @@ def __init__(self, f) -> None:
     def __call__(self, *args):
         ret = self.f(*args)
         if not ret and get_errno():
-            raise PyperclipWindowsException("Error calling " + self.f.__name__)
+            raise PyperclipWindowsException(f"Error calling {self.f.__name__}")
         return ret
 
     def __setattr__(self, key, value):

pandas/io/formats/css.py

@@ -198,7 +198,7 @@ class CSSResolver:
             for prop in ["", "top", "right", "bottom", "left"]
         },
         **{
-            "-".join(["border", prop]): _side_expander("border-{:s}-" + prop)
+            "-".join(["border", prop]): _side_expander(f"border-{{:s}}-{prop}")
             for prop in ["color", "style", "width"]
         },
         **{

pandas/io/formats/format.py

@@ -256,7 +256,7 @@ def to_string(self) -> str:
 
         fmt_values = [i.strip() for i in fmt_values]
         values = ", ".join(fmt_values)
-        result = ["[" + values + "]"]
+        result = [f"[{values}]"]
         if self.footer:
             footer = self._get_footer()
             if footer:
@@ -417,10 +417,10 @@ def to_string(self) -> str:
             result = self.adj.adjoin(3, fmt_values)
 
         if self.header and have_header:
-            result = fmt_index[0] + "\n" + result
+            result = f"{fmt_index[0]}\n{result}"
 
         if footer:
-            result += "\n" + footer
+            result += f"\n{footer}"
 
         return str("".join(result))
 
@@ -936,7 +936,7 @@ def space_format(x, y):
                     and need_leadsp[x]
                     and not restrict_formatting
                 ):
-                    return " " + y
+                    return f" {y}"
                 return y
 
             str_columns = list(
@@ -951,7 +951,7 @@ def space_format(x, y):
             dtypes = self.frame.dtypes
             need_leadsp = dict(zip(fmt_columns, map(is_numeric_dtype, dtypes)))
             str_columns = [
-                [" " + x if not self._get_formatter(i) and need_leadsp[x] else x]
+                [f" {x}" if not self._get_formatter(i) and need_leadsp[x] else x]
                 for i, x in enumerate(fmt_columns)
             ]
         # self.str_columns = str_columns
@@ -1534,7 +1534,7 @@ def format_values_with(float_format):
             # default formatter leaves a space to the left when formatting
             # floats, must be consistent for left-justifying NaNs (GH #25061)
             if self.justify == "left":
-                na_rep = " " + self.na_rep
+                na_rep = f" {self.na_rep}"
             else:
                 na_rep = self.na_rep
 
@@ -1726,7 +1726,7 @@ def format_percentiles(
 
     if np.all(int_idx):
         out = percentiles_round_type.astype(str)
-        return [i + "%" for i in out]
+        return [f"{i}%" for i in out]
 
     unique_pcts = np.unique(percentiles)
     to_begin = unique_pcts[0] if unique_pcts[0] > 0 else None
@@ -1741,7 +1741,7 @@ def format_percentiles(
     out[int_idx] = percentiles[int_idx].round().astype(int).astype(str)
 
     out[~int_idx] = percentiles[~int_idx].round(prec).astype(str)
-    return [i + "%" for i in out]
+    return [f"{i}%" for i in out]
 
 
 def is_dates_only(values: np.ndarray | DatetimeArray | Index | DatetimeIndex) -> bool:
@@ -1929,7 +1929,7 @@ def _make_fixed_width(
     def just(x: str) -> str:
         if conf_max is not None:
             if (conf_max > 3) & (adjustment.len(x) > max_len):
-                x = x[: max_len - 3] + "..."
+                x = f"{x[:max_len - 3]}..."
         return x
 
     strings = [just(x) for x in strings]
@@ -2004,7 +2004,7 @@ def should_trim(values: np.ndarray | list[str]) -> bool:
 
     # leave one 0 after the decimal points if need be.
     result = [
-        x + "0" if is_number_with_decimal(x) and x.endswith(decimal) else x
+        f"{x}0" if is_number_with_decimal(x) and x.endswith(decimal) else x
         for x in trimmed
     ]
     return result

pandas/io/formats/printing.py

@@ -156,7 +156,7 @@ def _pprint_dict(
         )
 
     if nitems < len(seq):
-        return fmt.format(things=", ".join(pairs) + ", ...")
+        return fmt.format(things=f"{', '.join(pairs)}, ...")
     else:
         return fmt.format(things=", ".join(pairs))
 
@@ -339,7 +339,7 @@ def format_object_summary(
     if line_break_each_value:
         # If we want to vertically align on each value of obj, we need to
         # separate values by a line break and indent the values
-        sep = ",\n " + " " * len(name)
+        sep = f",\n {' ' * len(name)}"
     else:
         sep = ","
     max_seq_items = get_option("display.max_seq_items") or n
@@ -427,16 +427,16 @@ def best_len(values: list[str]) -> int:
         line = space2
 
         for head_value in head:
-            word = head_value + sep + " "
+            word = f"{head_value + sep} "
             summary, line = _extend_line(summary, line, word, display_width, space2)
 
         if is_truncated:
             # remove trailing space of last line
-            summary += line.rstrip() + space2 + "..."
+            summary += f"{line.rstrip() + space2}..."
             line = space2
 
         for tail_item in tail[:-1]:
-            word = tail_item + sep + " "
+            word = f"{tail_item + sep} "
             summary, line = _extend_line(summary, line, word, display_width, space2)
 
         # last value: no sep added + 1 space of width used for trailing ','
@@ -445,7 +445,7 @@ def best_len(values: list[str]) -> int:
 
         # right now close is either '' or ', '
         # Now we want to include the ']', but not the maybe space.
-        close = "]" + close.rstrip(" ")
+        close = f"]{close.rstrip(' ')}"
         summary += close
 
         if len(summary) > (display_width) or line_break_each_value:
@@ -454,7 +454,7 @@ def best_len(values: list[str]) -> int:
             summary += " "
 
         # remove initial space
-        summary = "[" + summary[len(space2) :]
+        summary = f"[{summary[len(space2):]}"
 
     return summary