New lines strike again with append_nuclide

[MicahGale]

Describe the bug

In certain circumstances when you add a new nuclide to an existing material, and then write it out to file again invalid syntax is created.

To Reproduce

This uses the demo model from MontePy.

problem = montepy.read_input("demo/pin_cell.imcnp")
uranium = problem.materials[1]
if "O-16" not in uranium:
    for comp_idx in range(len(uranium)):
        uranium.values[comp_idx] *= 1/3
    uranium.add_nuclide("O-16.80c", 2/3)
problem.write_to_file("new_pin_cell.imcnp")

MCNP Original input file snippet

If applicable, please include a small section of the input file you were working on. If it includes any specific values please change or remove them. For example:

Made up PWR pin Cell Problem
c uranium rod 
1    1  10.0   -1     101 -102 imp:n=1
c gas gap
2    0           1  -2 101 -102 imp:n=1
c cladding
3    10 5.0     2  -3 101 -102 imp:n=1
c water cell
5    2  1.0    2     101 -102
                       103 -104
                       105 -106 imp:n=1

1 CZ 0.39
2 CZ 0.40
3 CZ 0.46
101 PZ -0.63
102 PZ  0.63
103 PX -0.63
104 PX  0.63
105 PY -0.63
106 PY  0.63

M1    92235.80c 0.04 
      92238.80c 0.96
M2     1001.80c 0.66
       8016.80c 0.33
M10   40090.80c 0.515
      40091.80c 0.112
      40092.80c 0.171
      40094.80c 0.174
      40096.80c 0.028
mode n
nps 1e3 

Outputs:

c .... 
M1    92235.80c 0.01
      92238.80c 0.328016.80c   0.6666666666666666
c ...

Version

• Version 1.0.0a1