pola-rs/polars

Checks I have checked that this issue has not already been reported. I have confirmed this bug exists on the latest version of Polars. Reproducible example import polars as pl df = pl.DataFrame({"a": [1.5, 2.5, 3.5]}) out = df.write_csv(float_scientific=True, decimal_comma=True, separator=";") # actual 'a\n1,5e0\n1,5e02,5e0\n1,5e02,5e03,5e0\n' # expected 'a\n1,5e0\n2,5e0\n3,5e0\n' Log output actual : 'a\n1,5e0\n1,5e02,5e0\n1,5e02,5e03,5e0\n' expected: 'a\n1,5e0\n2,5e0\n3,5e0\n' [{'a': '1,5e0'}, {'a': '1,5e02,5e0'}, {'a': '1,5e02,5e03,5e0'}] Traceback (most recent call last): File "/home/koen/my-polars/fuzz/findings/mre_io_csv_float_scientific_decimal_comma.py", line 19, in <module> assert out == "a\n1,5e0\n2,5e0\n3,5e0\n", "SILENT WRITER CORRUPTION" ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ AssertionError: SILENT WRITER CORRUPTION also, $ cat tt.csv a 1,5e0 1,5e02,5e0 1,5e02,5e03,5e0 Issue description Incorrect formatting. Expected behavior See repro. Installed versi

Checks I have checked that this issue has not already been reported. I have confirmed this bug exists on the latest version of Polars. Reproducible example import polars as pl tmp_path = "./tmp" df = pl.DataFrame( { "p": [10, 10, 20, 20], "a": [1, 2, 3, None], "b": [False, False, True, None] } ) df.write_delta( tmp_path, delta_write_options={"partition_by": "p"}, ) expr = pl.col.a.is_null() out = pl.scan_delta(tmp_path).filter(expr).collect() # filter works expr = pl.col.b.is_null() out = pl.scan_delta(tmp_path).filter(expr).collect() # filter does not work expr = pl.col.b == pl.lit(False) out = pl.scan_delta(tmp_path).filter(expr).collect() Log output $ POLARS_VERBOSE=1 pp issue_bool_mre.py 2>&1 | grep skipping initialize_scan_predicate: Predicate pushdown allows skipping 1 / 2 files initialize_scan_predicate: Predicate pushdown allows skipping 1 / 2 files initialize_scan_predicate: Predicate pushdown allows skipping 0 / 2 files Issue