Question: This seems like a straight-forward question but I can't seem to pinpoint my problem. I am trying to delete all lines in a file that start with an octothorpe (#) except the first line. Here is the loop I am working with:

```
for i, line in enumerate(input_file):
    if i > 1:
        if not line.startswith('#'):
            output.write(line)

```

The above code doesn't seem to work. Does anyone known what my problem is? Thanks!

Answer: 
You aren't writing out the first line:

```
for i, line in enumerate(input_file):
    if i == 0:
        output.write(line)
    else:
        if not line.startswith('#'):
            output.write(line)

```

Keep in mind also that `enumerate` (like most things) starts at zero.

A little more concisely (and not repeating the output line):

```
for i, line in enumerate(input_file):
    if i == 0 or not line.startswith('#'):
        output.write(line)

```
Maybe you want to omit lines from the output where the first *non-whitespace* character is an octothorpe:

```
for i, line in enumerate(input_file):
    if i == 0 or not line.lstrip().startswith('#'):
        output.write(line)

```

(note the call to `lstrip`)