I worked with PHP for a while and I found it to behave like you describe: I rarely found bugs in code once it reached a stable state. I haven't used Python (I m

I worked with PHP for a while and I found it to behave like you describe: I rarely found bugs in code once it reached a stable state. I haven't used Python (I might be the only one), so I can only speculate on whether it's truly more bug-prone than PHP. But one possible reason could be the relatively straightforward behavior of PHP, and C code. (My experience is with non-OO PHP, mainly from hacking Drupal modules, which might make a difference). C and (older) PHP have a small number of data types and few or no hidden behaviors. Neither is OO. I wonder if OO might contribute to long-term instability, because since OO languages are rich in types, they tend to let the language make inferences and allow types to alter the meaning of syntax. For predictable code, you probably want a language that isn't too smart and always gives the same meaning to the same code.