import os
import shutil
import re

ch4F = "./ch4"
files = os.listdir(ch4F)
prefixes = {f[:-6] for f in files if f.endswith("_1.png")}

for prefix in prefixes:
    dest_dir = os.path.join(ch4F, prefix)
    os.makedirs(dest_dir, exist_ok=True)
    for fname in list(files):
        if fname.startswith(prefix + "_") or fname == f"{prefix}.png":
            shutil.move(os.path.join(ch4F, fname),
                        os.path.join(dest_dir, fname))
    files = os.listdir(ch4F)

pattern0 = re.compile(r"^(.+)_0\.png$")
for fname in files:
    m = pattern0.match(fname)
    if not m:
        continue
    prefix = m.group(1)
    variants = [f for f in files if f.startswith(prefix + "_") and f != fname]
    if not variants:
        src = os.path.join(ch4F, fname)
        dst = os.path.join(ch4F, f"{prefix}.png")
        os.rename(src, dst)
        files = os.listdir(ch4F)