I want to use only tabs without space
\t\t...\tdef
not
\t \tdef
or
\t\t def
I want to use only tabs without space
\t\t...\tdef
not
\t \tdef
or
\t\t def
So long as you are using noexpandtab, vim will only add spaces when 'tabbing' manually if the setting of the softtabstop option does not equal the tabstop option value.
Similarly, vim won't use spaces when you use the << or >> commands if you use the same setting for shiftwidth as you do tabstop.
vim won't stop you from adding spaces inbetween tabs if you really try. If you want to spot these you can make occasional use of the :set list command or even use a syntax highlight rule to show them. (The sequence '\t ' is usually 'wrong'.)