Question

I have to read a data file that contains numbers formatted with (very) old FORTRAN style. A line of the file looks like this:

 4.500000+1 1.894719-3 4.600000+1 8.196721-3 4.700000+1 2.869539-3

The file (or large portion of it) contains these numbers in a fixed width format. The trouble with reading these numbers in Python is that there is no E in these numbers. Watch what happens:

>>> float('4.50000+1')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: invalid literal for float(): 4.50000+1

I can write a parser to read this, but wanted to know if this has already be done. This is an old FORTRAN format so I thought perhaps someone had already figured it out. Does anyone know of a library to read numbers like this?

Answer 1

this should work:

In [47]: strs="4.500000+1 1.894719-3 4.600000+1 8.196721-3 4.700000+1 2.869539-3"

In [48]: [float(x.replace("+","e+").replace("-","e-")) for x in strs.split()]

Out[48]: [45.0, 0.001894719, 46.0, 0.008196721, 47.0, 0.002869539]