Any popularity in Python over Ruby stems largely from the fact that Python came first.
I've heard Python developer's working on a Ruby on Rails application that the problem with Ruby is that approximately equivalent to Python in terms of productivity. They wanted to use Python, but pragmatically you can't make the case to management to switch from one language to the other if the other language is more or less the same. But most of the time this effect works the other way around, where Python was established before Ruby.
I was doing Perl in 1999, and looked at switching to Ruby or Python. Python was still quite small back then, but you had web frameworks (Zope, Twisted), albeit the incarnations back then are clunky by today's standards, but Python was establishing itself as a clean, readable, dynamic language. Ruby on the other hand had no web frameworks, and almost no documentation in English - the only reason I was considering it was because I was working with a Japanese localization team and they thought Ruby was quite hot.
The debate over which dynamic or scripting language to use was always between Perl and Python back then. Perl was the incumbent and Python the challenger, Ruby rarely factored into the picture. It wasn't until Rails started to become useable and gain attention in 2004 and 2005 that Ruby interest started to really blossom. And so Python was well established for many uses: scientific computing, ad-hoc data processing, network programming. If you're a development manager of an application that you want to make scriptable, you would have made the decision to already go with Python, there just isn't any compelling reason to switch to Ruby beyond the sake of switching.
Another example is IronPython versus IronRuby: work started on IronPython in 2003, work started on IronRuby in 2007. IronPython is at version 2.0, while IronRuby is at version 0.5, and this is reflected in the polish of these language implementations. A .Net developer might decide that they prefer the idiosyncracies of Ruby over Python's idiosyncracies, but if they had to start a large project in today, they'd most likely choose IronPython since there is much less risk of the project bumping up against the rough edges of IronPython versus IronRuby.
I've heard Python developer's working on a Ruby on Rails application that the problem with Ruby is that approximately equivalent to Python in terms of productivity. They wanted to use Python, but pragmatically you can't make the case to management to switch from one language to the other if the other language is more or less the same. But most of the time this effect works the other way around, where Python was established before Ruby.
I was doing Perl in 1999, and looked at switching to Ruby or Python. Python was still quite small back then, but you had web frameworks (Zope, Twisted), albeit the incarnations back then are clunky by today's standards, but Python was establishing itself as a clean, readable, dynamic language. Ruby on the other hand had no web frameworks, and almost no documentation in English - the only reason I was considering it was because I was working with a Japanese localization team and they thought Ruby was quite hot.
The debate over which dynamic or scripting language to use was always between Perl and Python back then. Perl was the incumbent and Python the challenger, Ruby rarely factored into the picture. It wasn't until Rails started to become useable and gain attention in 2004 and 2005 that Ruby interest started to really blossom. And so Python was well established for many uses: scientific computing, ad-hoc data processing, network programming. If you're a development manager of an application that you want to make scriptable, you would have made the decision to already go with Python, there just isn't any compelling reason to switch to Ruby beyond the sake of switching.
Another example is IronPython versus IronRuby: work started on IronPython in 2003, work started on IronRuby in 2007. IronPython is at version 2.0, while IronRuby is at version 0.5, and this is reflected in the polish of these language implementations. A .Net developer might decide that they prefer the idiosyncracies of Ruby over Python's idiosyncracies, but if they had to start a large project in today, they'd most likely choose IronPython since there is much less risk of the project bumping up against the rough edges of IronPython versus IronRuby.