Shell perl python

Shell: an interface that directly interacts with the Linux kernel. It is relatively basic and used to process basic and simple tasks, such as batch processing.
Perl: it is more complex and powerful than shell, and has a powerful regular expression matching engine. It has strong string mode matching capabilities and is good at processing text and strings. The code reading is not very good, this requires careful design when writing large applications. The purpose is to solve the appropriate problems in an appropriate way. If perl is not appropriate, use other more appropriate tools.
Python: more abstract, more powerful functions, better object-oriented support, and clearer Code (the purpose is to use only one of the best solutions for a problem), with a large library.