All of this can be achieved in Python without additional libraries using list and generator comprehensions - this library just provides some extra syntactic sugar.
There are many thing in here that are already in functools, itertools (!), or the standard builtins (!!). Please do not shadow builtin names, and consider removing things that are already in itertools, as they will be faster than pure-Python code.
Yes, that decisions look dirty and dubious, but using funcy for several months, I've come to that practicality and convenience is worth it.
Some of itertools things are just reexports and builtins are extended purely - so that they behave the same given same arguments - with negligible performance overhead.
Anyway, if you are such a purist you still have at least two options:
1. just `import funcy` and use it as `funcy.map(...)` or `funcy.keep(...)`
2. Import only functions you use, avioding name clashes, use `from funcy import map as xmap` to import extended builtins.