aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/python/pytest/py3/_pytest/_io/wcwidth.py
blob: 6efbe654d6c5c5d9f71268537e2d28902741d64a (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
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