Formats a datetime object, allowing for a dash modifier to be used, stripping leading zeros from a value

templatefilters.py

def dateformat(dt, format='%-I:%m %p, %A, %B %-d, %Y'):
    # Remove leading zeros if the identifier has a dash in front of it
    # Implemented in Python, as in strftime it's platform-dependent
    if format.find('%-') != -1:
        compiled = ''

        i = 0
        length = len(format)
        fmt = None
        fmt_remove_leading = False
        while i < length:
            c = format[i]
            if fmt is None:
                if c == '%':
                    fmt = '%'
                else:
                    compiled += c
            else:
                if c == '-' and fmt == '%':
                    fmt_remove_leading = True
                elif c.isdigit():
                    fmt += c
                elif c.isdigit() or c in '_^': # Accounts for GNU C flags
                    fmt += c
                    fmt_compiled = dt.strftime(fmt)
                    if fmt_remove_leading:
                        fmt_compiled = fmt_compiled.lstrip('0')
                    compiled += fmt_compiled
                    fmt = None
                    fmt_remove_leading = False
                else:
                    compiled += fmt
                    fmt = None
                    fmt_remove_leading = False
            i += 1

        compiled += fmt or ''
        return compiled

    else:
        return dt.strftime(format)