contrib: refactor preparation logic for patterns of check-code.py This is a part of preparation to apply checking with check-code.py on code fragments embedded in *.t test scripts. Before this patch, preparation logic in _preparepats() of check-code.py is not reusable. It can handle only module global list "checks". This patch splits preparation logic into small internal functions, and add the loop to invoke them, in order to increase reusability of the logic. "c[-2]" is equivalent to "c[3]" for "checks". This patch uses the former, because it will be more reusable for subsequent patch than the latter.

contrib: split pypats list in check-code.py This is a part of preparation to apply checking with check-code.py on code fragments embedded in *.t test scripts. Ideally, all patterns in "pypats" before this patch should be applied on not only normal *.py files but also code fragments embedded in *.t test scripts. But fixing test scripts for some patterns requires many changes, and has less profit than effort. Therefore, this patch splits pypats list into two below: - commonpypats, which are applied on all (= including code fragments embedded in *.t test scripts) *.py files - pypats, which are applied only on normal *.py

tests: remove useless line wrapping in a code fragment embedded in test script This is a part of preparation to apply checking with check-code.py on code fragments embedded in *.t test scripts. This revision avoids error of check-code.py below. Use () to wrap long lines in Python, not \