56 lines
1.2 KiB
Python
56 lines
1.2 KiB
Python
|
import unicodedata
|
||
|
from functools import lru_cache
|
||
|
|
||
|
|
||
|
@lru_cache(100)
|
||
|
def wcwidth(c: str) -> int:
|
||
|
"""Determine how many columns are needed to display a character in a terminal.
|
||
|
|
||
|
Returns -1 if the character is not printable.
|
||
|
Returns 0, 1 or 2 for other characters.
|
||
|
"""
|
||
|
o = ord(c)
|
||
|
|
||
|
# ASCII fast path.
|
||
|
if 0x20 <= o < 0x07F:
|
||
|
return 1
|
||
|
|
||
|
# Some Cf/Zp/Zl characters which should be zero-width.
|
||
|
if (
|
||
|
o == 0x0000
|
||
|
or 0x200B <= o <= 0x200F
|
||
|
or 0x2028 <= o <= 0x202E
|
||
|
or 0x2060 <= o <= 0x2063
|
||
|
):
|
||
|
return 0
|
||
|
|
||
|
category = unicodedata.category(c)
|
||
|
|
||
|
# Control characters.
|
||
|
if category == "Cc":
|
||
|
return -1
|
||
|
|
||
|
# Combining characters with zero width.
|
||
|
if category in ("Me", "Mn"):
|
||
|
return 0
|
||
|
|
||
|
# Full/Wide east asian characters.
|
||
|
if unicodedata.east_asian_width(c) in ("F", "W"):
|
||
|
return 2
|
||
|
|
||
|
return 1
|
||
|
|
||
|
|
||
|
def wcswidth(s: str) -> int:
|
||
|
"""Determine how many columns are needed to display a string in a terminal.
|
||
|
|
||
|
Returns -1 if the string contains non-printable characters.
|
||
|
"""
|
||
|
width = 0
|
||
|
for c in unicodedata.normalize("NFC", s):
|
||
|
wc = wcwidth(c)
|
||
|
if wc < 0:
|
||
|
return -1
|
||
|
width += wc
|
||
|
return width
|