Question

Here is a problem.

I have a .py file and a .txt.
To simplify, my .txt looks like:

@x@

In the .py I have

x=15

I would like to replace @x@ in the txt by the value saved in the py, ie my txt should look like

15

I tried with this:

for i, line in enumerate(fileinput.input('mytxtfile.txt', inplace = 1)):
    sys.stdout.write(line.replace('@x@', 'x'))

or with

for i, line in enumerate(fileinput.input('mytxtfile.txt', inplace = 1)):
    sys.stdout.write(line.replace('@x@', 'str(x)'))

The problem is that the “replace” method seems to consider only strings and I need to evaluate the value of the string.
Any idea how to do it?

Thanks

Answer 1

just leave the quotes off str(x)

for i, line in enumerate(fileinput.input('mytxtfile.txt', inplace = 1)): 
    sys.stdout.write(line.replace('@x@', str(x)))

If you want more control over the output you can use a format string. Eg for 2 decimal places

for i, line in enumerate(fileinput.input('mytxtfile.txt', inplace = 1)): 
    sys.stdout.write(line.replace('@x@', "%.2f"%x))