From bfec4bbb3185409425e7f002b51c77a97d6fb004 Mon Sep 17 00:00:00 2001
From: Thomas Li <thomasli1234567890@gmail.com>
Date: Thu, 12 Dec 2019 16:39:52 -0800
Subject: [PATCH 1/3] CLN: use f-strings instead in pandas/util subdir

---
 pandas/util/_decorators.py      | 19 +++++++----------
 pandas/util/_depr_module.py     | 20 +++++++-----------
 pandas/util/_doctools.py        |  2 +-
 pandas/util/_print_versions.py  | 14 ++++++-------
 pandas/util/_test_decorators.py | 15 ++++++-------
 pandas/util/_validators.py      | 37 ++++++++++++---------------------
 6 files changed, 42 insertions(+), 65 deletions(-)

diff --git a/pandas/util/_decorators.py b/pandas/util/_decorators.py
index 2684b90e33b7e..2e91d76b0fe98 100644
--- a/pandas/util/_decorators.py
+++ b/pandas/util/_decorators.py
@@ -84,18 +84,13 @@ def wrapper(*args, **kwargs) -> Callable[..., Any]:
         if empty1 or empty2 and not summary:
             raise AssertionError(doc_error_msg)
         wrapper.__doc__ = dedent(
-            """
-        {summary}
-
-        .. deprecated:: {depr_version}
-            {depr_msg}
-
-        {rest_of_docstring}"""
-        ).format(
-            summary=summary.strip(),
-            depr_version=version,
-            depr_msg=msg,
-            rest_of_docstring=dedent(doc),
+            f"""
+        {summary.strip()}
+
+        .. deprecated:: {version}
+            {msg}
+
+        {dedent(doc)}"""
         )
 
     return wrapper
diff --git a/pandas/util/_depr_module.py b/pandas/util/_depr_module.py
index ae3c6359d20e0..99dafdd760d26 100644
--- a/pandas/util/_depr_module.py
+++ b/pandas/util/_depr_module.py
@@ -61,17 +61,15 @@ def __getattr__(self, name):
 
         if self.removals is not None and name in self.removals:
             warnings.warn(
-                "{deprmod}.{name} is deprecated and will be removed in "
-                "a future version.".format(deprmod=self.deprmod, name=name),
+                f"{self.deprmod}.{name} is deprecated and will be removed in "
+                "a future version.",
                 FutureWarning,
                 stacklevel=2,
             )
         elif self.moved is not None and name in self.moved:
             warnings.warn(
-                "{deprmod} is deprecated and will be removed in "
-                "a future version.\nYou can access {name} as {moved}".format(
-                    deprmod=self.deprmod, name=name, moved=self.moved[name]
-                ),
+                f"{self.deprmod} is deprecated and will be removed in "
+                f"a future version.\nYou can access {name} as {self.moved[name]}",
                 FutureWarning,
                 stacklevel=2,
             )
@@ -79,8 +77,8 @@ def __getattr__(self, name):
             deprmodto = self.deprmodto
             if deprmodto is False:
                 warnings.warn(
-                    "{deprmod}.{name} is deprecated and will be removed in "
-                    "a future version.".format(deprmod=self.deprmod, name=name),
+                    f"{self.deprmod}.{name} is deprecated and will be removed in "
+                    "a future version.",
                     FutureWarning,
                     stacklevel=2,
                 )
@@ -89,10 +87,8 @@ def __getattr__(self, name):
                     deprmodto = obj.__module__
                 # The object is actually located in another module.
                 warnings.warn(
-                    "{deprmod}.{name} is deprecated. Please use "
-                    "{deprmodto}.{name} instead.".format(
-                        deprmod=self.deprmod, name=name, deprmodto=deprmodto
-                    ),
+                    f"{self.deprmod}.{name} is deprecated. Please use "
+                    f"{deprmodto}.{name} instead.",
                     FutureWarning,
                     stacklevel=2,
                 )
diff --git a/pandas/util/_doctools.py b/pandas/util/_doctools.py
index 11156bc972857..91972fed7a3bb 100644
--- a/pandas/util/_doctools.py
+++ b/pandas/util/_doctools.py
@@ -113,7 +113,7 @@ def _insert_index(self, data):
             data.insert(0, "Index", data.index)
         else:
             for i in range(idx_nlevels):
-                data.insert(i, "Index{0}".format(i), data.index._get_level_values(i))
+                data.insert(i, f"Index{i}", data.index._get_level_values(i))
 
         col_nlevels = data.columns.nlevels
         if col_nlevels > 1:
diff --git a/pandas/util/_print_versions.py b/pandas/util/_print_versions.py
index d1c74e8530245..b9f7e0c69f8b6 100644
--- a/pandas/util/_print_versions.py
+++ b/pandas/util/_print_versions.py
@@ -40,14 +40,14 @@ def get_sys_info() -> List[Tuple[str, Optional[Union[str, int]]]]:
             [
                 ("python", ".".join(map(str, sys.version_info))),
                 ("python-bits", struct.calcsize("P") * 8),
-                ("OS", "{sysname}".format(sysname=sysname)),
-                ("OS-release", "{release}".format(release=release)),
+                ("OS", f"{sysname}"),
+                ("OS-release", f"{release}"),
                 # ("Version", "{version}".format(version=version)),
-                ("machine", "{machine}".format(machine=machine)),
-                ("processor", "{processor}".format(processor=processor)),
-                ("byteorder", "{byteorder}".format(byteorder=sys.byteorder)),
-                ("LC_ALL", "{lc}".format(lc=os.environ.get("LC_ALL", "None"))),
-                ("LANG", "{lang}".format(lang=os.environ.get("LANG", "None"))),
+                ("machine", f"{machine}"),
+                ("processor", f"{processor}"),
+                ("byteorder", f"{sys.byteorder}"),
+                ("LC_ALL", f"{os.environ.get('LC_ALL', 'None')}"),
+                ("LANG", f"{os.environ.get('LANG', 'None')}"),
                 ("LOCALE", ".".join(map(str, locale.getlocale()))),
             ]
         )
diff --git a/pandas/util/_test_decorators.py b/pandas/util/_test_decorators.py
index 7669e729995d0..0e3ea25bf6fdb 100644
--- a/pandas/util/_test_decorators.py
+++ b/pandas/util/_test_decorators.py
@@ -129,7 +129,7 @@ def skip_if_installed(package: str) -> Callable:
         The name of the package.
     """
     return pytest.mark.skipif(
-        safe_import(package), reason="Skipping because {} is installed.".format(package)
+        safe_import(package), reason=f"Skipping because {package} is installed."
     )
 
 
@@ -163,9 +163,9 @@ def skip_if_no(package: str, min_version: Optional[str] = None) -> Callable:
         a pytest.mark.skipif to use as either a test decorator or a
         parametrization mark.
     """
-    msg = "Could not import '{}'".format(package)
+    msg = f"Could not import '{package}'"
     if min_version:
-        msg += " satisfying a min_version of {}".format(min_version)
+        msg += f" satisfying a min_version of {min_version}"
     return pytest.mark.skipif(
         not safe_import(package, min_version=min_version), reason=msg
     )
@@ -181,20 +181,17 @@ def skip_if_no(package: str, min_version: Optional[str] = None) -> Callable:
     is_platform_windows(), reason="not used on win32"
 )
 skip_if_has_locale = pytest.mark.skipif(
-    _skip_if_has_locale(),
-    reason="Specific locale is set {lang}".format(lang=locale.getlocale()[0]),
+    _skip_if_has_locale(), reason=f"Specific locale is set {locale.getlocale()[0]}",
 )
 skip_if_not_us_locale = pytest.mark.skipif(
-    _skip_if_not_us_locale(),
-    reason="Specific locale is set {lang}".format(lang=locale.getlocale()[0]),
+    _skip_if_not_us_locale(), reason=f"Specific locale is set {locale.getlocale()[0]}",
 )
 skip_if_no_scipy = pytest.mark.skipif(
     _skip_if_no_scipy(), reason="Missing SciPy requirement"
 )
 skip_if_no_ne = pytest.mark.skipif(
     not _USE_NUMEXPR,
-    reason="numexpr enabled->{enabled}, "
-    "installed->{installed}".format(enabled=_USE_NUMEXPR, installed=_NUMEXPR_INSTALLED),
+    reason=f"numexpr enabled->{_USE_NUMEXPR}, " f"installed->{_NUMEXPR_INSTALLED}",
 )
 
 
diff --git a/pandas/util/_validators.py b/pandas/util/_validators.py
index 0eaf46d563163..cbfab83d0429c 100644
--- a/pandas/util/_validators.py
+++ b/pandas/util/_validators.py
@@ -26,13 +26,8 @@ def _check_arg_length(fname, args, max_fname_arg_count, compat_args):
         argument = "argument" if max_arg_count == 1 else "arguments"
 
         raise TypeError(
-            "{fname}() takes at most {max_arg} {argument} "
-            "({given_arg} given)".format(
-                fname=fname,
-                max_arg=max_arg_count,
-                argument=argument,
-                given_arg=actual_arg_count,
-            )
+            f"{fname}() takes at most {max_arg_count} {argument} "
+            f"({actual_arg_count} given)"
         )
 
 
@@ -71,9 +66,9 @@ def _check_for_default_values(fname, arg_val_dict, compat_args):
         if not match:
             raise ValueError(
                 (
-                    "the '{arg}' parameter is not "
+                    f"the '{key}' parameter is not "
                     "supported in the pandas "
-                    "implementation of {fname}()".format(fname=fname, arg=key)
+                    f"implementation of {fname}()"
                 )
             )
 
@@ -132,10 +127,7 @@ def _check_for_invalid_keys(fname, kwargs, compat_args):
     if diff:
         bad_arg = list(diff)[0]
         raise TypeError(
-            (
-                "{fname}() got an unexpected "
-                "keyword argument '{arg}'".format(fname=fname, arg=bad_arg)
-            )
+            (f"{fname}() got an unexpected " f"keyword argument '{bad_arg}'")
         )
 
 
@@ -223,8 +215,7 @@ def validate_args_and_kwargs(fname, args, kwargs, max_fname_arg_count, compat_ar
     for key in args_dict:
         if key in kwargs:
             raise TypeError(
-                "{fname}() got multiple values for keyword "
-                "argument '{arg}'".format(fname=fname, arg=key)
+                f"{fname}() got multiple values for keyword " f"argument '{key}'"
             )
 
     kwargs.update(args_dict)
@@ -235,8 +226,8 @@ def validate_bool_kwarg(value, arg_name):
     """ Ensures that argument passed in arg_name is of type bool. """
     if not (is_bool(value) or value is None):
         raise ValueError(
-            'For argument "{arg}" expected type bool, received '
-            "type {typ}.".format(arg=arg_name, typ=type(value).__name__)
+            f'For argument "{arg_name}" expected type bool, received '
+            f"type {type(value).__name__}."
         )
     return value
 
@@ -289,9 +280,7 @@ def validate_axis_style_args(data, args, kwargs, arg_name, method_name):
     # First fill with explicit values provided by the user...
     if arg_name in kwargs:
         if args:
-            msg = "{} got multiple values for argument '{}'".format(
-                method_name, arg_name
-            )
+            msg = f"{method_name} got multiple values for argument '{arg_name}'"
             raise TypeError(msg)
 
         axis = data._get_axis_name(kwargs.get("axis", 0))
@@ -332,8 +321,8 @@ def validate_axis_style_args(data, args, kwargs, arg_name, method_name):
         out[data._AXIS_NAMES[0]] = args[0]
         out[data._AXIS_NAMES[1]] = args[1]
     else:
-        msg = "Cannot specify all of '{}', 'index', 'columns'."
-        raise TypeError(msg.format(arg_name))
+        msg = f"Cannot specify all of '{arg_name}', 'index', 'columns'."
+        raise TypeError(msg)
     return out
 
 
@@ -365,8 +354,8 @@ def validate_fillna_kwargs(value, method, validate_scalar_dict_value=True):
     elif value is not None and method is None:
         if validate_scalar_dict_value and isinstance(value, (list, tuple)):
             raise TypeError(
-                '"value" parameter must be a scalar or dict, but '
-                'you passed a "{0}"'.format(type(value).__name__)
+                f'"value" parameter must be a scalar or dict, but '
+                'you passed a "{type(value).__name__}"'
             )
 
     elif value is not None and method is not None:

From b9a91ee9859c2fc28580504b16e66bbe394dc291 Mon Sep 17 00:00:00 2001
From: Thomas Li <thomasli1234567890@gmail.com>
Date: Thu, 12 Dec 2019 17:02:30 -0800
Subject: [PATCH 2/3] add files from pandas/io/formats

---
 pandas/io/formats/css.py   | 13 +++++-----
 pandas/io/formats/excel.py | 19 +++++++-------
 pandas/io/formats/style.py | 51 ++++++++++++++------------------------
 3 files changed, 33 insertions(+), 50 deletions(-)

diff --git a/pandas/io/formats/css.py b/pandas/io/formats/css.py
index 6bc5f56bb5f7f..583dd49d4c66a 100644
--- a/pandas/io/formats/css.py
+++ b/pandas/io/formats/css.py
@@ -18,8 +18,7 @@ def expand(self, prop, value):
             mapping = self.SIDE_SHORTHANDS[len(tokens)]
         except KeyError:
             warnings.warn(
-                'Could not expand "{prop}: {val}"'.format(prop=prop, val=value),
-                CSSWarning,
+                f'Could not expand "{prop}: {value}"', CSSWarning,
             )
             return
         for key, idx in zip(self.SIDES, mapping):
@@ -110,14 +109,14 @@ def __call__(self, declarations_str, inherited=None):
 
         # 3. TODO: resolve other font-relative units
         for side in self.SIDES:
-            prop = "border-{side}-width".format(side=side)
+            prop = f"border-{side}-width"
             if prop in props:
                 props[prop] = self.size_to_pt(
                     props[prop], em_pt=font_size, conversions=self.BORDER_WIDTH_RATIOS
                 )
             for prop in [
-                "margin-{side}".format(side=side),
-                "padding-{side}".format(side=side),
+                f"margin-{side}",
+                f"padding-{side}",
             ]:
                 if prop in props:
                     # TODO: support %
@@ -206,9 +205,9 @@ def _error():
 
         val = round(val, 5)
         if int(val) == val:
-            size_fmt = "{fmt:d}pt".format(fmt=int(val))
+            size_fmt = f"{int(val):d}pt"
         else:
-            size_fmt = "{fmt:f}pt".format(fmt=val)
+            size_fmt = f"{val:f}pt"
         return size_fmt
 
     def atomize(self, declarations):
diff --git a/pandas/io/formats/excel.py b/pandas/io/formats/excel.py
index 5d8573c1341f5..2f7a80eea1554 100644
--- a/pandas/io/formats/excel.py
+++ b/pandas/io/formats/excel.py
@@ -91,6 +91,7 @@ def build_xlstyle(self, props):
             "font": self.build_font(props),
             "number_format": self.build_number_format(props),
         }
+
         # TODO: handle cell width and height: needs support in pandas.io.excel
 
         def remove_none(d):
@@ -132,12 +133,10 @@ def build_border(self, props):
         return {
             side: {
                 "style": self._border_style(
-                    props.get("border-{side}-style".format(side=side)),
-                    props.get("border-{side}-width".format(side=side)),
-                ),
-                "color": self.color_to_excel(
-                    props.get("border-{side}-color".format(side=side))
+                    props.get(f"border-{side}-style"),
+                    props.get(f"border-{side}-width"),
                 ),
+                "color": self.color_to_excel(props.get(f"border-{side}-color")),
             }
             for side in ["top", "right", "bottom", "left"]
         }
@@ -427,7 +426,7 @@ def _format_value(self, val):
             if missing.isposinf_scalar(val):
                 val = self.inf_rep
             elif missing.isneginf_scalar(val):
-                val = "-{inf}".format(inf=self.inf_rep)
+                val = f"-{self.inf_rep}"
             elif self.float_format is not None:
                 val = float(self.float_format % val)
         if getattr(val, "tzinfo", None) is not None:
@@ -509,8 +508,8 @@ def _format_header_regular(self):
             if has_aliases:
                 if len(self.header) != len(self.columns):
                     raise ValueError(
-                        "Writing {cols} cols but got {alias} "
-                        "aliases".format(cols=len(self.columns), alias=len(self.header))
+                        f"Writing {len(self.columns)} cols but got {len(self.header)} "
+                        "aliases"
                     )
                 else:
                     colnames = self.header
@@ -718,8 +717,8 @@ def write(
         if num_rows > self.max_rows or num_cols > self.max_cols:
             raise ValueError(
                 "This sheet is too large! Your sheet size is: "
-                + "{}, {} ".format(num_rows, num_cols)
-                + "Max sheet size is: {}, {}".format(self.max_rows, self.max_cols)
+                f"{num_rows}, {num_cols} "
+                f"Max sheet size is: {self.max_rows}, {self.max_cols}"
             )
 
         if isinstance(writer, ExcelWriter):
diff --git a/pandas/io/formats/style.py b/pandas/io/formats/style.py
index a45045991e879..d3a12ccb77048 100644
--- a/pandas/io/formats/style.py
+++ b/pandas/io/formats/style.py
@@ -165,7 +165,7 @@ def default_display_func(x):
             if self.na_rep is not None and pd.isna(x):
                 return self.na_rep
             elif is_float(x):
-                display_format = "{0:.{precision}f}".format(x, precision=self.precision)
+                display_format = f"{x:.{self.precision}f}"
                 return display_format
             else:
                 return x
@@ -293,7 +293,7 @@ def format_attr(pair):
             name = self.data.columns.names[r]
             cs = [
                 BLANK_CLASS if name is None else INDEX_NAME_CLASS,
-                "level{lvl}".format(lvl=r),
+                f"level{r}",
             ]
             name = BLANK_VALUE if name is None else name
             row_es.append(
@@ -310,8 +310,8 @@ def format_attr(pair):
                 for c, value in enumerate(clabels[r]):
                     cs = [
                         COL_HEADING_CLASS,
-                        "level{lvl}".format(lvl=r),
-                        "col{col}".format(col=c),
+                        f"level{r}",
+                        f"col{c}",
                     ]
                     cs.extend(
                         cell_context.get("col_headings", {}).get(r, {}).get(c, [])
@@ -339,7 +339,7 @@ def format_attr(pair):
             index_header_row = []
 
             for c, name in enumerate(self.data.index.names):
-                cs = [INDEX_NAME_CLASS, "level{lvl}".format(lvl=c)]
+                cs = [INDEX_NAME_CLASS, f"level{c}"]
                 name = "" if name is None else name
                 index_header_row.append(
                     {"type": "th", "value": name, "class": " ".join(cs)}
@@ -358,8 +358,8 @@ def format_attr(pair):
             for c, value in enumerate(rlabels[r]):
                 rid = [
                     ROW_HEADING_CLASS,
-                    "level{lvl}".format(lvl=c),
-                    "row{row}".format(row=r),
+                    f"level{c}",
+                    f"row{r}",
                 ]
                 es = {
                     "type": "th",
@@ -377,7 +377,7 @@ def format_attr(pair):
                 row_es.append(es)
 
             for c, col in enumerate(self.data.columns):
-                cs = [DATA_CLASS, "row{row}".format(row=r), "col{col}".format(col=c)]
+                cs = [DATA_CLASS, f"row{r}", f"col{c}"]
                 cs.extend(cell_context.get("data", {}).get(r, {}).get(c, []))
                 formatter = self._display_funcs[(r, c)]
                 value = self.data.iloc[r, c]
@@ -399,12 +399,7 @@ def format_attr(pair):
                         props.append(x.split(":"))
                     else:
                         props.append(["", ""])
-                cellstyle.append(
-                    {
-                        "props": props,
-                        "selector": "row{row}_col{col}".format(row=r, col=c),
-                    }
-                )
+                cellstyle.append({"props": props, "selector": f"row{r}_col{c}"})
             body.append(row_es)
 
         table_attr = self.table_attributes
@@ -971,9 +966,7 @@ def hide_columns(self, subset):
 
     @staticmethod
     def _highlight_null(v, null_color):
-        return (
-            "background-color: {color}".format(color=null_color) if pd.isna(v) else ""
-        )
+        return f"background-color: {null_color}" if pd.isna(v) else ""
 
     def highlight_null(self, null_color="red"):
         """
@@ -1126,9 +1119,7 @@ def relative_luminance(rgba):
             def css(rgba):
                 dark = relative_luminance(rgba) < text_color_threshold
                 text_color = "#f1f1f1" if dark else "#000000"
-                return "background-color: {b};color: {c};".format(
-                    b=colors.rgb2hex(rgba), c=text_color
-                )
+                return f"background-color: {colors.rgb2hex(rgba)};color: {text_color};"
 
             if s.ndim == 1:
                 return [css(rgba) for rgba in rgbas]
@@ -1160,7 +1151,7 @@ def set_properties(self, subset=None, **kwargs):
         >>> df.style.set_properties(color="white", align="right")
         >>> df.style.set_properties(**{'background-color': 'yellow'})
         """
-        values = ";".join("{p}: {v}".format(p=p, v=v) for p, v in kwargs.items())
+        values = ";".join(f"{p}: {v}" for p, v in kwargs.items())
         f = lambda x: values
         return self.applymap(f, subset=subset)
 
@@ -1191,12 +1182,9 @@ def css_bar(start, end, color):
             if end > start:
                 css += "background: linear-gradient(90deg,"
                 if start > 0:
-                    css += " transparent {s:.1f}%, {c} {s:.1f}%, ".format(
-                        s=start, c=color
-                    )
-                css += "{c} {e:.1f}%, transparent {e:.1f}%)".format(
-                    e=min(end, width), c=color
-                )
+                    css += f" transparent {start:.1f}%, {color} {start:.1f}%, "
+                e = min(end, width)
+                css += f"{color} {e:.1f}%, transparent {e:.1f}%)"
             return css
 
         def css(x):
@@ -1358,7 +1346,7 @@ def _highlight_extrema(data, color="yellow", max_=True):
         """
         Highlight the min or max in a Series or DataFrame.
         """
-        attr = "background-color: {0}".format(color)
+        attr = f"background-color: {color}"
 
         if max_:
             extrema = data == np.nanmax(data.to_numpy())
@@ -1528,10 +1516,7 @@ def _maybe_wrap_formatter(formatter, na_rep: Optional[str]):
     elif callable(formatter):
         formatter_func = formatter
     else:
-        msg = (
-            "Expected a template string or callable, got {formatter} "
-            "instead".format(formatter=formatter)
-        )
+        msg = f"Expected a template string or callable, got {formatter} instead"
         raise TypeError(msg)
 
     if na_rep is None:
@@ -1539,5 +1524,5 @@ def _maybe_wrap_formatter(formatter, na_rep: Optional[str]):
     elif isinstance(na_rep, str):
         return lambda x: na_rep if pd.isna(x) else formatter_func(x)
     else:
-        msg = "Expected a string, got {na_rep} instead".format(na_rep=na_rep)
+        msg = f"Expected a string, got {na_rep} instead"
         raise TypeError(msg)

From 710916485da49b70145528de2438746fc23b5779 Mon Sep 17 00:00:00 2001
From: Thomas Li <thomasli1234567890@gmail.com>
Date: Thu, 12 Dec 2019 20:02:20 -0800
Subject: [PATCH 3/3] Fix errors

---
 pandas/util/_tester.py     | 2 +-
 pandas/util/_validators.py | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/pandas/util/_tester.py b/pandas/util/_tester.py
index 7822ecdeeb4d8..6a3943cab692e 100644
--- a/pandas/util/_tester.py
+++ b/pandas/util/_tester.py
@@ -22,7 +22,7 @@ def test(extra_args=None):
             extra_args = [extra_args]
         cmd = extra_args
     cmd += [PKG]
-    print("running: pytest {}".format(" ".join(cmd)))
+    print(f"running: pytest {' '.join(cmd)}")
     sys.exit(pytest.main(cmd))
 
 
diff --git a/pandas/util/_validators.py b/pandas/util/_validators.py
index cbfab83d0429c..8b675a6b688fe 100644
--- a/pandas/util/_validators.py
+++ b/pandas/util/_validators.py
@@ -354,8 +354,8 @@ def validate_fillna_kwargs(value, method, validate_scalar_dict_value=True):
     elif value is not None and method is None:
         if validate_scalar_dict_value and isinstance(value, (list, tuple)):
             raise TypeError(
-                f'"value" parameter must be a scalar or dict, but '
-                'you passed a "{type(value).__name__}"'
+                '"value" parameter must be a scalar or dict, but '
+                f'you passed a "{type(value).__name__}"'
             )
 
     elif value is not None and method is not None: