Exclude character from string in regex Python [on hold]

I want to check the pattern of my variable in python.

I want to include a-zA-Z0-9 but it should exlude i,I.

Length of the variable should be 4.

So My pattern for regex is ^[a-zA-Z0-9][^iI_]{4}$ but it is not working.

E.g.
Expectred Result

• A001- True
• A00I- False
• A1019- False