Module, block or whatever to scope variables without explicitly listing them? [duplicate]

Question

In larger notebooks I have often trouble with conflicting variable names. To combat this there are Modules and blocks. But with those you always have to list the variables you are using. I don't understand the need for this. Is there an alternative where you just open a scope of some kind, and everything is local to that scope? That's a feature of pretty much every other programming language has and I'm desperately missing.

Answer 1

Begin may be what you need here, as it allows you to define variables inside a given Context:

a = 3;
Begin["MyContext`"];
{a, b, c} = {1, 2, 3};
Print@{a, b, c};
End[];
Print@{a, b, c}
Print@{MyContext`a, MyContext`b, MyContext`c}

{1,2,3}

{1,b,c}

{MyContext`a,2,3}

There are a couple of important caveats: If you have already given a variable a name in the Global` context, then you cannot define a variable in the new context with that exact same name. Also, when leaving the new context, the defined variables are not cleared, for that you need to do ClearAll["MyContext`*"] after you End[]