Yeah I would agree that a decent (a few steps below good in my book) programmer should be able to have a decent handle on a new language, given some acclimatization time of course. The amount of time this period lasts varies on the language said programmer is learning, as well as the languages he knows. If they are far different (say going from object oriented to functional) it will take longer to learn. But it's not to say that after learning it, his code will be bad. Maybe not as good as experts, but not bad.
But I would say the jump from "not bad" code to "good" code; or the jump from "good" code to "great" code are huge leaps. And in a badly designed language, it could be argued that even the best code is lacking. To say that language doesn't matter at all is extremely silly, otherwise we wouldn't have 5 million languages. Most languages are created, not just for the fun of it, but to solve something lacking in what is available elsewhere. (OK, there are a lot of languages people have created just because they are geeks, but most languages that people actually use are purposeful). Python was created to have something easier than perl and more powerful than bash to write shell scripts with and automate system administration tasks. PHP was created to enhance html with a powerful integrated server language that was easier than c but not alien to it. It was a replacement for cgi. For me, php is far too flat, making it pretty tough to navigate and get a handle on. If you know what you want to do, it probably has something to fit that task, but for exploring it's not fun. I rather enjoy python, where I can play around at the interpreter and try new things. PHP also is not very strict when it comes to types, even less strict than python, and in my newbieness that has caused me loads of problems. But I know people who swear by PHP, and I admit it has been used for many great sites, so it can't be that bad. Still, outside of the web sphere, it is a bit odd to use PHP. Not necesarily bad, just a bit odd. And there are situations that are a bit odd for python also (sound editing,etc).
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