filesize: simplify the logic

Don't handle the "gnu" format specially, instead include the separating
space directly in the unit suffix.

Also just break out of the loop when the suffix is known; the final
return statement is the same one as the one(s) formerly inside the loop.

Signed-off-by: Beat Bolli <dev@drbeat.li>

src/humanize/filesize.py

@@ -4,8 +4,8 @@
 from __future__ import annotations
 
 suffixes = {
-    "decimal": ("kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"),
-    "binary": ("KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB"),
+    "decimal": (" kB", " MB", " GB", " TB", " PB", " EB", " ZB", " YB"),
+    "binary": (" KiB", " MiB", " GiB", " TiB", " PiB", " EiB", " ZiB", " YiB"),
     "gnu": "KMGTPEZY",
 }
 
@@ -74,12 +74,7 @@ def naturalsize(
     for i, s in enumerate(suffix):
         unit = base ** (i + 2)
 
-        if abs_bytes < unit and not gnu:
-            return (format + " %s") % ((base * bytes_ / unit), s)
+        if abs_bytes < unit:
+            break
 
-        if abs_bytes < unit and gnu:
-            return (format + "%s") % ((base * bytes_ / unit), s)
-
-    if gnu:
-        return (format + "%s") % ((base * bytes_ / unit), s)
-    return (format + " %s") % ((base * bytes_ / unit), s)
+    return format % (base * bytes_ / unit) + s