Format number using LaTeX notation in Python

Question

Using format strings in Python I can easily print a number in \"scientific notation\", e.g.

>> print \'%g\'%1e9
1e+09

What is the simples

Answer 1

You can write a frexp10 function:

def frexp10(x):
    exp = int(math.floor(math.log10(abs(x))))
    return x / 10**exp, exp

Formatting in LaTeX style is then:

'{0}^{{{1:+03}}}'.format(*frexp10(-1.234e9))