reconvert Namespace Reference

Functions
def	convert
def	quote
def	main

Variables
int	append = 1
list	__all__ = ["convert","quote"]
dictionary	mastertable

Function Documentation

def reconvert.convert	(		s,
			syntax = None
	)

Convert a regex regular expression to re syntax.

The first argument is the regular expression, as a string object,
just like it would be passed to regex.compile().  (I.e., pass the
actual string object -- string quotes must already have been
removed and the standard escape processing has already been done,
e.g. by eval().)

The optional second argument is the regex syntax variant to be
used.  This is an integer mask as passed to regex.set_syntax();
the flag bits are defined in regex_syntax.  When not specified, or
when None is given, the current regex syntax mask (as retrieved by
regex.get_syntax()) is used -- which is 0 by default.

The return value is a regular expression, as a string object that
could be passed to re.compile().  (I.e., no string quotes have
been added -- use quote() below, or repr().)

The conversion is not always guaranteed to be correct.  More
syntactical analysis should be performed to detect borderline
cases and decide what to do with them.  For example, 'x*?' is not
translated correctly.

Definition at line 90 of file reconvert.py.

def convert(s, syntax=None):
    """Convert a regex regular expression to re syntax.

    The first argument is the regular expression, as a string object,
    just like it would be passed to regex.compile().  (I.e., pass the
    actual string object -- string quotes must already have been
    removed and the standard escape processing has already been done,
    e.g. by eval().)

    The optional second argument is the regex syntax variant to be
    used.  This is an integer mask as passed to regex.set_syntax();
    the flag bits are defined in regex_syntax.  When not specified, or
    when None is given, the current regex syntax mask (as retrieved by
    regex.get_syntax()) is used -- which is 0 by default.

    The return value is a regular expression, as a string object that
    could be passed to re.compile().  (I.e., no string quotes have
    been added -- use quote() below, or repr().)

    The conversion is not always guaranteed to be correct.  More
    syntactical analysis should be performed to detect borderline
    cases and decide what to do with them.  For example, 'x*?' is not
    translated correctly.

    """
    table = mastertable.copy()
    if syntax is None:
        syntax = regex.get_syntax()
    if syntax & RE_NO_BK_PARENS:
        del table[r'\('], table[r'\)']
        del table['('], table[')']
    if syntax & RE_NO_BK_VBAR:
        del table[r'\|']
        del table['|']
    if syntax & RE_BK_PLUS_QM:
        table['+'] = r'\+'
        table['?'] = r'\?'
        table[r'\+'] = '+'
        table[r'\?'] = '?'
    if syntax & RE_NEWLINE_OR:
        table['\n'] = '|'
    res = ""

    i = 0
    end = len(s)
    while i < end:
        c = s[i]
        i = i+1
        if c == '\\':
            c = s[i]
            i = i+1
            key = '\\' + c
            key = table.get(key, key)
            res = res + key
        else:
            c = table.get(c, c)
            res = res + c
    return res