TString::Form/Format in PyRoot

ROOT
1

Hi,

I am trying to use both Form and Format from TString in pyroot. In C++ I see:

root [0] TString str
(TString &) ""[0]
root [1] str.Form("%.3f",1.3)
root [2] 
root [2] str
(TString &) "1.300"[5]
root [3] 
root [3] auto str1 = TString::Format("%.3f", 1.3)
(class TString &) "1.300"[5]
root [4] 
root [4]

And in python:

>>> import ROOT
>>> 
>>> str1=ROOT.TString()
>>> str1.Form("%.3f",1.3)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: void TString::Form(const char* fmt) =>
    takes at most 1 arguments (2 given)
>>> 
>>> str2=ROOT.TString.Format("%.3f",1.3)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: static TString TString::Format(const char* fmt) =>
    takes at most 1 arguments (2 given)

I don’t understand why this doesn’t work. I am using root 6.06.06-x86_64-slc6-gcc49-opt in Debian.

Cheers.

2

The reason is simple. There is no mapping between C[++] functions with variable number of arguments and Python.
For this kind of functionality Python is certainly orders of magnitude better than C++ and ROOT. So, I would recommend to use the Python native functionality.