Question

I want to implement a HashMap in Python. I want to ask a user for an input. depending on his input I am retrieving some information from the HashMap. If the user enters a key of the HashMap, I would like to retrieve the corresponding value.

How do I implement this functionality in Python?

HashMap<String,String> streetno=new HashMap<String,String>();
   streetno.put("1", "Sachin Tendulkar");
   streetno.put("2", "Dravid");
   streetno.put("3","Sehwag");
   streetno.put("4","Laxman");
   streetno.put("5","Kohli")

Answer 1

Python dictionary is a built-in type that supports key-value pairs. It’s the nearest builtin data structure relative to Java’s HashMap.

You can declare a dict with key-value pairs set to values:

streetno = {
    "1": "Sachin Tendulkar",
    "2": "Dravid",
    "3": "Sehwag",
    "4": "Laxman",
    "5": "Kohli"
}

You can also set a key-value mapping after creation:

streetno = {}
streetno["1"] = "Sachin Tendulkar"
print(streetno["1"]) # => "Sachin Tendulkar"

Another way to create a dictionary is with the dict() builtin function, but this only works when your keys are valid identifiers:

streetno = dict(one="Sachin Tendulkar", two="Dravid")
print(streetno["one"]) # => "Sachin Tendulkar"