What is the output of the following snippet of code?
```
code = ['# this is a python code',
'x = 0',
'print(x)',
'for i in range(x):',
' x = x + 1',
'print(x)']
mod_code = []
for line in code:
if 'print' in line:
# there is a single space between the middle quotes
line = '#' + ' ' + line
mod_code.append(line)
for line in mod_code:
print(line)
```