I have this Python code:
# some_dic is a dictionary
value = some_dic.get(var_name, None)
How can I do the same in Crystal?
The map type called dictionary in Python is called Hash in Crystal.
Values with an explicit fallback value can be retrieved using the Hash#fetch method:
numbers = {"Alice" => "0123", "Bob" => "0124"}
puts numbers.fetch("Charlie", "0000")
So in your case
value = some_dic.fetch(var_name, nil)
If your default value should be nil then there's the handy Hash#[]? method:
puts numbers["Charlie"]?
Read more about hashes in the language introduction: https://crystal-lang.org/reference/1.3/syntax_and_semantics/literals/hash.html