Enforce ruff/refurb rules (FURB) (pydata#10367)

* Apply ruff/refurb rule FURB136

FURB136 Replace `x if x >= y else y` with `max(x, y)`

* Apply ruff/refurb rule FURB167

FURB167 Use of regular expression alias

The abbreviated flags seem less readable, although experienced
programers might know the abbreviated flags match inline flags.

* Enforce ruff/refurb rules (FURB)

Author: DimitriPapadopoulos

pyproject.toml

@@ -258,6 +258,7 @@ extend-select = [
   "TID",  # flake8-tidy-imports (absolute imports)
   "PGH",  # pygrep-hooks
   "PERF", # Perflint
+  "FURB", # refurb
   "RUF",
 ]
 extend-safe-fixes = [
@@ -270,6 +271,7 @@ ignore = [
   "C40",     # unnecessary generator, comprehension, or literal
   "PIE790",  # unnecessary pass statement
   "PERF203", # try-except within a loop incurs performance overhead
+  "FURB105", # unnecessary empty string passed to `print`
   "RUF001",  # string contains ambiguous unicode character
   "RUF002",  # docstring contains ambiguous acute accent unicode character
   "RUF003",  # comment contains ambiguous no-break space unicode character

xarray/core/accessor_str.py

@@ -1944,7 +1944,7 @@ def replace(
         if regex:
             pat = self._re_compile(pat=pat, flags=flags, case=case)
             func = lambda x, ipat, irepl, i_n: ipat.sub(
-                repl=irepl, string=x, count=i_n if i_n >= 0 else 0
+                repl=irepl, string=x, count=max(i_n, 0)
             )
         else:
             pat = self._stringify(pat)

xarray/tests/test_accessor_str.py

@@ -906,7 +906,7 @@ def test_extractall_single_single_nocase(dtype) -> None:
     pat_re: str | bytes = (
         pat_str if dtype == np.str_ else bytes(pat_str, encoding="UTF-8")
     )
-    pat_compiled = re.compile(pat_re, flags=re.I)
+    pat_compiled = re.compile(pat_re, flags=re.IGNORECASE)
 
     value = xr.DataArray(
         [["a_Xy_0", "ab_xY_10", "abc_Xy_01"], ["abcd_Xy_", "", "abcdef_Xy_101"]],
@@ -981,7 +981,7 @@ def test_extractall_single_multi_nocase(dtype) -> None:
     pat_re: str | bytes = (
         pat_str if dtype == np.str_ else bytes(pat_str, encoding="UTF-8")
     )
-    pat_compiled = re.compile(pat_re, flags=re.I)
+    pat_compiled = re.compile(pat_re, flags=re.IGNORECASE)
 
     value = xr.DataArray(
         [
@@ -1063,7 +1063,7 @@ def test_extractall_multi_single_nocase(dtype) -> None:
     pat_re: str | bytes = (
         pat_str if dtype == np.str_ else bytes(pat_str, encoding="UTF-8")
     )
-    pat_compiled = re.compile(pat_re, flags=re.I)
+    pat_compiled = re.compile(pat_re, flags=re.IGNORECASE)
 
     value = xr.DataArray(
         [["a_Xy_0", "ab_xY_10", "abc_Xy_01"], ["abcd_Xy_", "", "abcdef_Xy_101"]],
@@ -1145,7 +1145,7 @@ def test_extractall_multi_multi_nocase(dtype) -> None:
     pat_re: str | bytes = (
         pat_str if dtype == np.str_ else bytes(pat_str, encoding="UTF-8")
     )
-    pat_compiled = re.compile(pat_re, flags=re.I)
+    pat_compiled = re.compile(pat_re, flags=re.IGNORECASE)
 
     value = xr.DataArray(
         [
@@ -1245,7 +1245,7 @@ def test_findall_single_single_case(dtype) -> None:
 
 def test_findall_single_single_nocase(dtype) -> None:
     pat_str = r"(\w+)_Xy_\d*"
-    pat_re = re.compile(dtype(pat_str), flags=re.I)
+    pat_re = re.compile(dtype(pat_str), flags=re.IGNORECASE)
 
     value = xr.DataArray(
         [["a_Xy_0", "ab_xY_10", "abc_Xy_01"], ["abcd_Xy_", "", "abcdef_Xy_101"]],
@@ -1313,7 +1313,7 @@ def test_findall_single_multi_case(dtype) -> None:
 
 def test_findall_single_multi_nocase(dtype) -> None:
     pat_str = r"(\w+)_Xy_\d*"
-    pat_re = re.compile(dtype(pat_str), flags=re.I)
+    pat_re = re.compile(dtype(pat_str), flags=re.IGNORECASE)
 
     value = xr.DataArray(
         [
@@ -1387,7 +1387,7 @@ def test_findall_multi_single_case(dtype) -> None:
 
 def test_findall_multi_single_nocase(dtype) -> None:
     pat_str = r"(\w+)_Xy_(\d*)"
-    pat_re = re.compile(dtype(pat_str), flags=re.I)
+    pat_re = re.compile(dtype(pat_str), flags=re.IGNORECASE)
 
     value = xr.DataArray(
         [["a_Xy_0", "ab_xY_10", "abc_Xy_01"], ["abcd_Xy_", "", "abcdef_Xy_101"]],
@@ -1463,7 +1463,7 @@ def test_findall_multi_multi_case(dtype) -> None:
 
 def test_findall_multi_multi_nocase(dtype) -> None:
     pat_str = r"(\w+)_Xy_(\d*)"
-    pat_re = re.compile(dtype(pat_str), flags=re.I)
+    pat_re = re.compile(dtype(pat_str), flags=re.IGNORECASE)
 
     value = xr.DataArray(
         [