From d8d447c487a363a0a8e4c019ec71806e69b1cbac Mon Sep 17 00:00:00 2001 From: "codeflash-ai[bot]" <148906541+codeflash-ai[bot]@users.noreply.github.com> Date: Tue, 3 Jun 2025 23:44:28 +0000 Subject: [PATCH] =?UTF-8?q?=E2=9A=A1=EF=B8=8F=20Speed=20up=20method=20`Cha?= =?UTF-8?q?racterRemover.remove=5Fcontrol=5Fcharacters`=20by=2046%=20Here?= =?UTF-8?q?=E2=80=99s=20an=20optimized=20version=20of=20your=20program.=20?= =?UTF-8?q?The=20main=20bottleneck=20is=20`re.sub`,=20which=20is=20relativ?= =?UTF-8?q?ely=20slow=20for=20simple=20tasks=20like=20filtering=20ASCII=20?= =?UTF-8?q?ranges,=20especially=20in=20tight=20loops.=20You=20can=20greatl?= =?UTF-8?q?y=20speed=20this=20up=20by=20using=20`str.translate`=20with=20a?= =?UTF-8?q?=20translation=20table=20that=20drops=20the=20unwanted=20contro?= =?UTF-8?q?l=20characters.=20This=20avoids=20regex=20overhead=20and=20is?= =?UTF-8?q?=20much=20faster=20in=20practice.?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit **Why is this faster?** - `str.translate` does pure C-level translation and omission in a single pass, no regex engine overhead. - The translation table is created only once per instance. - No function-call overhead inside loops. **Guaranteed same results:** Control chars `chr(0)`–`chr(31)` and `chr(127)` are omitted, just as with your regex. This will significantly reduce the time per call as shown in your profile. If you want even more speed and you're always working with ASCII, you can potentially use bytes, but `str.translate` is already highly efficient for this use case. --- code_to_optimize/remove_control_chars.py | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/code_to_optimize/remove_control_chars.py b/code_to_optimize/remove_control_chars.py index 45f67459e..f80661913 100644 --- a/code_to_optimize/remove_control_chars.py +++ b/code_to_optimize/remove_control_chars.py @@ -1,10 +1,15 @@ -import re - - class CharacterRemover: def __init__(self): self.version = "0.1" + # Build translation table once in init. + self._ctrl_table = self._make_ctrl_table() def remove_control_characters(self, s) -> str: """Remove control characters from the string.""" - return re.sub("[\\x00-\\x1F\\x7F]", "", s) if s else "" + return s.translate(self._ctrl_table) if s else "" + + def _make_ctrl_table(self): + # Map delete (ASCII 127) and 0-31 to None + ctrl_chars = dict.fromkeys(range(32), None) + ctrl_chars[127] = None + return str.maketrans(ctrl_chars)