Python's popularity

[walterbyrd]

I have read that python is the world's 3rd most popular language, and
that python has surpassed perl in popularity, but I am not seeing it.

>From what I have seen:

- in unix/linux sysadmin, perl is far more popular than python,
windows sysadmins typically don't use either.
- in web-development, php is far more popular than python - it's not
even close.
- when I did a search on dice, I found over 20X more jobs advertised
for ruby on rails developers, than for python dango developers.
- application development is dominated by java, c/c++, and maybe a
little visual basic.
- as I understand it, fortran is still the most popular language for
numberical programming.

Of course, these are just observations on my part, nothing scientific
about it. But, I can't help but wonder how python's popularity was
determined. I suspect that a lot of people use python as a secondary
skill. For example, I use ms-word, but I'm not an ms-word
professional.

Please note: I am not confusing popularity with quality. I am not
saying that php is better for web-dev, or anything like that. I am
just wondering how python is rated as being so popular, when python
does not seem to dominate anything.