[reportlab-users] What arguments does fp_str expect?

[Peter]

Hi all,

Earlier today, I had a problem in the fp_str function in
reportlab/lib/utils.py where it was being passed three floats held as
strings (perhaps an RGB color tuple, I have not checked yet).  The
root problem may have been elsewhere (possibly in my own code), but it
would help to know what arguments this function expects.  There is no
docstring, but the comment at the top suggests string arguments might
be expected.

This sample code shows the issue I am having.  This is what I expected
to happen:


>>> from reportlab.lib.utils import fp_str

>>> fp_str([0.123, 1.23, 12.3])

'.123 1.23 12.3'

>>> fp_str((0.123, 1.23, 12.3))

'.123 1.23 12.3'

>>> fp_str(["0.123", "1.23", "12.3"])

'.123 1.23 12.3'

>>> fp_str(("0.123", "1.23", "12.3"))

'.123 1.23 12.3'

However, the last two examples fail with a TypeError from the abs line
(see below):


>>> abs("0.123")

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: bad operand type for abs(): 'str'

This is my copy of the relevant part of reportlab/lib/utils.py, with
two lines of
code changed to include a float() conversion.  Otherwise it looks the same
as that in SVN I think:
http://svn.reportlab.com/cgi-bin/viewvc.cgi/public/reportlab/trunk/src/reportlab/lib/utils.py?view=log

try:
    #raise ImportError
    ### NOTE!  FP_STR SHOULD PROBABLY ALWAYS DO A PYTHON STR()
CONVERSION ON ARGS
    ### IN CASE THEY ARE "LAZY OBJECTS".  ACCELLERATOR DOESN'T DO THIS (YET)
    try:
        from _rl_accel import fp_str                # in case of builtin version
    except ImportError:
        from reportlab.lib._rl_accel import fp_str  # specific
except ImportError:
    from math import log
    _log_10 = lambda x,log=log,_log_e_10=log(10.0): log(x)/_log_e_10
    _fp_fmts = "%.0f", "%.1f", "%.2f", "%.3f", "%.4f", "%.5f", "%.6f"
    import re
    _tz_re = re.compile('0+$')
    del re
    def fp_str(*a):
        """Returns a space separated string of the given numbers."""
#PJC: extend this please
        if len(a)==1 and isSeqType(a[0]): a = a[0]
        s = []
        A = s.append
        for i in a:
            sa =abs(float(i)) #PJC change to add float
            if sa<=1e-7: A('0')
            else:
                l = sa<=1 and 6 or min(max(0,(6-int(_log_10(sa)))),6)
                n = _fp_fmts[l]%float(i) #PJC change to add float
                if l:
                    n = _tz_re.sub('',n)
                    try:
                        if n[-1]=='.': n = n[:-1]
                    except:
                        print i, n
                        raise
                A((n[0]!='0' or len(n)==1) and n or n[1:])
        return string.join(s)


So, should the fp_str function cope with a sequence of numbers as
strings (i.e. a list or tuple of strings)?  If so, is my simple minded
fix appropriate for when the _rl_accel module isn't being used?

If not, then I will have to digg a little deeper into my problem to
work out why I have a list/tuple of strings instead of a list/tuple of
floats.

Thanks,

Peter