Asking about the dict in numba

Dear Numba team I have using your library to optimize my code but when I apply it, I caught a trouble. Can you help me to fix it?

@jit
def encode2char_safe(input_lines, char_dict):
    unk = char_dict['<u>']
    forw_lines = [list(map(lambda m: list(map(lambda t: char_dict.get(t, unk), m)), line)) for line in input_lines]
    return forw_lines

and the error

numba.core.errors.TypingError: Failed in object mode pipeline (step: convert make_function into JIT functions)
Cannot capture the non-constant value associated with variable 'char_dict' in a function that will escape.

def encode2char_safe(input_lines, char_dict):
    <source elided>
    unk = char_dict['<u>']
    forw_lines = [list(map(lambda m: list(map(lambda t: char_dict.get(t, unk), m)), line)) for line in input_lines]
    ^

This error may have been caused by the following argument(s):
- argument 1: cannot determine Numba type of <class 'dict'>

can you help me to use numba to optimize my code. Thank you in advance and I hope to hearing from you soon.

[stuartarchibald]

I’m afraid that I don’t think there is a way to fix this without hitting more problems, perhaps take a look at the 5 minute guide to find out what Numba is best at and whether it’s a good fit for your problem? I’d also suggest trying to simplify code as much as possible, it makes it easier for Numba to work out what to do (i.e. maps with lambdas are really hard to analyse!).

[esc]

I will close this issue now, as I believe it has been resolved. If this is not the case, please don’t hesitate to reopen this or open a new one.