Jack Of All Trades, Master of Some
"Jack of all trades, master of none" is a figure of speech used in reference to a person who has dabbled in many skills, rather than gaining expertise by focusing on one.
The shortened version "a jack of all trades" is often a compliment for a person who is good at fixing things, and has a very good broad knowledge. They may be a master of integration, as such an individual who knows enough from many learned trades and skills to be able to bring the individual's disciplines together in a practical manner. This person is a generalist rather than a specialist.
Why have I altered the phrase and replaced "none" with "some"? Well, it defines me more accurately. When I dedicate myself to something, I can confidently say that I am often able to master it. Making me more of specialist rather than a generalist in certain disciplines.