[Tutor] How to convert a long decimal into a string?

[Dick Moores]

Here's a function I wrote some time ago, and just discovered that in 
one important category of cases, long numbers with a decimal point, 
it doesn't do what I intended.

=====================================================
def numberRounding(n, significantDigits=4):
	"""
	Rounds a number (float or integer, negative or positive) to any number of
	significant digits. If an integer, there is no limitation on it's size.
	"""
	import decimal
	def d(x):
		return decimal.Decimal(str(x))
	decimal.getcontext().prec = significantDigits
	return d(n)/1
======================================================

Now, print 
numberRounding(232.3452345230987987098709879087098709870987098745234, 
30) prints
232.345234523

whereas if the first argument is enclosed in quotes, it does what I 
indended. Thus:
print 
numberRounding('232.3452345230987987098709879087098709870987098745234', 
30) prints
232.345234523098798709870987909 .

So my question is, how can I revise numberRounding() so that it is 
not necessary to employ the quotes. Or alternatively, is there a way 
to non-manually put quotes around an argument that is a long decimal? 
If have no idea at all about the second. As for the first, I believe 
I could devise an algorithm for first converting n to an int (for 
example, multiplying the above n by 1000), converting to a string, 
putting the decimal point back in between indices 2 and 3, then using 
that string as n (thereby avoiding the use of quotes around n as the 
first argument). But I have the feeling that Python must have a way 
already built in. Does it?

Thanks,

Dick Moores