To answer your question, Python is several times more expressive than C++ given that is is a higher level language, and since fewer lines are needed for a given program it is likely to be quicker to write.
To quote Martelli from Google talking about how the Youtube startup outran Google Video's might so much that they had to buy them:
"Eventually we bought that little start up and we found how 20 developers ran circles around our hundreds of great developers. The solution was simple! Those 20 guys were using Python. We were using C++. So, that was YouTube and still is." [1]
Google took months to copy new YouTube features, while YouTube could catch up in a week after Google innovated.
[1] Google Books, search term 'python interviews google vs youtube'
2) I do use Python but mostly for administrative/deployment/similar tasks as a scripting language. I see no proof that Python is "several times more expressive". I would really appreciate if you could kindly point me to a real study that shows exactly how it is more expressive and on what in particular the time is saved (you can of course omit the examples where Python is used as a glue language to stitch together few math libraries written in C/++).
I do have my own experience. Of course it is statistically meaningless. My friend and I have implemented simple GUI desktop app (custom video player with some features) as a bet. My buddy did it in Python and I did it in Delphi. I won: 1 hour vs 4.
"An empirical comparison of c, c++, java, perl, python, rexx and tcl"
Lutz Prechelt
IEEE Computer 33 (10), 23-29, 2000
80 implementations of the same set of requirements, created by 74 different programmers in various languages, are compared for several properties, such as run time, memory consumption, source text length, comment density, program structure, reliability, and the amount of effort required for writing them. The results indicate that, for the given programming problem,“scripting languages”(Perl, Python, Rexx, Tcl) are more productive than conventional languages. In terms of run time and memory consumption, they often turn out better than Java and not much worse than C or C++. In general, the differences between languages tend to be smaller than the typical differences due to different programmers within the same language.
Did some reading. The first thing that puts me on alert about the result is this:
" Most programmers in the script group used the associative arrays provided by their language and stored the dictionary words to be retrieved by their number encodings"
For C++/non-scripting they either used plain arrays or custom build tree in one case. So they had to write lots of code.
Sorry but there are associative arrays in C++ standard library and search and this and that. Building the program they've specified would be a no brainer in modern C++. This article is irrelevant for current situation.
To quote Martelli from Google talking about how the Youtube startup outran Google Video's might so much that they had to buy them:
"Eventually we bought that little start up and we found how 20 developers ran circles around our hundreds of great developers. The solution was simple! Those 20 guys were using Python. We were using C++. So, that was YouTube and still is." [1]
Google took months to copy new YouTube features, while YouTube could catch up in a week after Google innovated.
[1] Google Books, search term 'python interviews google vs youtube'