CLN: 29547 replace old string formatting 5 (#31967)

Author: 3vts

pandas/tests/io/parser/test_c_parser_only.py

@@ -158,7 +158,7 @@ def test_precise_conversion(c_parser_only):
     # test numbers between 1 and 2
     for num in np.linspace(1.0, 2.0, num=500):
         # 25 decimal digits of precision
-        text = "a\n{0:.25}".format(num)
+        text = f"a\n{num:.25}"
 
         normal_val = float(parser.read_csv(StringIO(text))["a"][0])
         precise_val = float(
@@ -170,7 +170,7 @@ def test_precise_conversion(c_parser_only):
         actual_val = Decimal(text[2:])
 
         def error(val):
-            return abs(Decimal("{0:.100}".format(val)) - actual_val)
+            return abs(Decimal(f"{val:.100}") - actual_val)
 
         normal_errors.append(error(normal_val))
         precise_errors.append(error(precise_val))
@@ -299,9 +299,7 @@ def test_grow_boundary_at_cap(c_parser_only):
 
     def test_empty_header_read(count):
         s = StringIO("," * count)
-        expected = DataFrame(
-            columns=["Unnamed: {i}".format(i=i) for i in range(count + 1)]
-        )
+        expected = DataFrame(columns=[f"Unnamed: {i}" for i in range(count + 1)])
         df = parser.read_csv(s)
         tm.assert_frame_equal(df, expected)
 
@@ -489,7 +487,7 @@ def test_comment_whitespace_delimited(c_parser_only, capsys):
     captured = capsys.readouterr()
     # skipped lines 2, 3, 4, 9
     for line_num in (2, 3, 4, 9):
-        assert "Skipping line {}".format(line_num) in captured.err
+        assert f"Skipping line {line_num}" in captured.err
     expected = DataFrame([[1, 2], [5, 2], [6, 2], [7, np.nan], [8, np.nan]])
     tm.assert_frame_equal(df, expected)
 

pandas/tests/io/parser/test_common.py

@@ -957,7 +957,7 @@ def test_nonexistent_path(all_parsers):
     # gh-14086: raise more helpful FileNotFoundError
     # GH#29233 "File foo" instead of "File b'foo'"
     parser = all_parsers
-    path = "{}.csv".format(tm.rands(10))
+    path = f"{tm.rands(10)}.csv"
 
     msg = f"File {path} does not exist" if parser.engine == "c" else r"\[Errno 2\]"
     with pytest.raises(FileNotFoundError, match=msg) as e:
@@ -1872,7 +1872,7 @@ def test_internal_eof_byte_to_file(all_parsers):
     parser = all_parsers
     data = b'c1,c2\r\n"test \x1a    test", test\r\n'
     expected = DataFrame([["test \x1a    test", " test"]], columns=["c1", "c2"])
-    path = "__{}__.csv".format(tm.rands(10))
+    path = f"__{tm.rands(10)}__.csv"
 
     with tm.ensure_clean(path) as path:
         with open(path, "wb") as f:

pandas/tests/io/parser/test_compression.py

@@ -145,7 +145,7 @@ def test_invalid_compression(all_parsers, invalid_compression):
     parser = all_parsers
     compress_kwargs = dict(compression=invalid_compression)
 
-    msg = "Unrecognized compression type: {compression}".format(**compress_kwargs)
+    msg = f"Unrecognized compression type: {invalid_compression}"
 
     with pytest.raises(ValueError, match=msg):
         parser.read_csv("test_file.zip", **compress_kwargs)

pandas/tests/io/parser/test_encoding.py

@@ -45,7 +45,7 @@ def test_utf16_bom_skiprows(all_parsers, sep, encoding):
 4,5,6""".replace(
         ",", sep
     )
-    path = "__{}__.csv".format(tm.rands(10))
+    path = f"__{tm.rands(10)}__.csv"
     kwargs = dict(sep=sep, skiprows=2)
     utf8 = "utf-8"
 

pandas/tests/io/parser/test_multi_thread.py

@@ -41,9 +41,7 @@ def test_multi_thread_string_io_read_csv(all_parsers):
     num_files = 100
 
     bytes_to_df = [
-        "\n".join(
-            ["{i:d},{i:d},{i:d}".format(i=i) for i in range(max_row_range)]
-        ).encode()
+        "\n".join([f"{i:d},{i:d},{i:d}" for i in range(max_row_range)]).encode()
         for _ in range(num_files)
     ]
     files = [BytesIO(b) for b in bytes_to_df]

pandas/tests/io/parser/test_na_values.py

@@ -111,10 +111,11 @@ def f(i, v):
         elif i > 0:
             buf = "".join([","] * i)
 
-        buf = "{0}{1}".format(buf, v)
+        buf = f"{buf}{v}"
 
         if i < nv - 1:
-            buf = "{0}{1}".format(buf, "".join([","] * (nv - i - 1)))
+            joined = "".join([","] * (nv - i - 1))
+            buf = f"{buf}{joined}"
 
         return buf
 

pandas/tests/io/parser/test_parse_dates.py

@@ -1101,7 +1101,7 @@ def test_bad_date_parse(all_parsers, cache_dates, value):
     # if we have an invalid date make sure that we handle this with
     # and w/o the cache properly
     parser = all_parsers
-    s = StringIO(("{value},\n".format(value=value)) * 50000)
+    s = StringIO((f"{value},\n") * 50000)
 
     parser.read_csv(
         s,

pandas/tests/io/parser/test_read_fwf.py

@@ -260,7 +260,7 @@ def test_fwf_regression():
     # Turns out "T060" is parsable as a datetime slice!
     tz_list = [1, 10, 20, 30, 60, 80, 100]
     widths = [16] + [8] * len(tz_list)
-    names = ["SST"] + ["T{z:03d}".format(z=z) for z in tz_list[1:]]
+    names = ["SST"] + [f"T{z:03d}" for z in tz_list[1:]]
 
     data = """  2009164202000   9.5403  9.4105  8.6571  7.8372  6.0612  5.8843  5.5192
 2009164203000   9.5435  9.2010  8.6167  7.8176  6.0804  5.8728  5.4869

pandas/tests/io/pytables/conftest.py

@@ -6,7 +6,7 @@
 @pytest.fixture
 def setup_path():
     """Fixture for setup path"""
-    return "tmp.__{}__.h5".format(tm.rands(10))
+    return f"tmp.__{tm.rands(10)}__.h5"
 
 
 @pytest.fixture(scope="module", autouse=True)