Re: Efficient, built-in way to determine if string has non-ASCII chars outside ASCII 32-127, CRLF, Tab?

[MRAB]

On 01/11/2011 18:54, Duncan Booth wrote:

Steven D'Aprano<steve+comp.lang.pyt...@pearwood.info>  wrote:

LEGAL = ''.join(chr(n) for n in range(32, 128)) + '\n\r\t\f'
MASK = ''.join('\01' if chr(n) in LEGAL else '\0' for n in range(128))

# Untested
def is_ascii_text(text):
     for c in text:
         n = ord(c)
         if n>= len(MASK) or MASK[n] == '\0': return False
     return True


Optimizing it is left as an exercise :)

#untested
LEGAL = ''.join(chr(n) for n in range(32, 128)) + '\n\r\t\f'
MASK = [True if chr(n) in LEGAL else False for n in range(128)]

Instead of:

    True if chr(n) in LEGAL else False

why not:

    if chr(n) in LEGAL

# Untested
def is_ascii_text(text):
   try:
     return all(MASK[ord(c)] for c in text)
   except IndexError:
     return False

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