Where is the function of 'apply' always used?

[Terry Reedy]

"???" <iamzcyhit at gmail.com> wrote in message 
news:84cefd1a-58de-485b-b00b-77218d2d054c at c19g2000prf.googlegroups.com...
| I'am a beginner of Python.In the course of reading the Python book,I
| found the function:apply;But
| I don't understand its use.Help!

Apply has been deprecated.  It has been replaced by the use of *args in 
function calls.
It is only still present for old code and will disappear in 3.0.
So you do not need it and should ignore it for now.