CODEWITHSUNDEEP
python
Charith
Charith

Reputation: 445

Using print command Vs calling directly

I started learning about dictionaries in Python.

For the following dictionary:

nameMap={1: "Bob", 2: "Pete", 3: "Ben", 4: "Bud", 5:  "Russ"}

In order to obtain a value, the outputs are slightly different when using print(nameMap[1]) and nameMap[1].

Can you explain what is exactly going here?

Upvotes: 0

Views: 815

Answers (3)

oz19
oz19

Reputation: 1866

print(nameMap[1]) just prints the value out on console (or whatever output system you're using).

nameMap[1] just returns the value contained by the dict, whatever the type is. In order to know what type the value is, type(nameMap[1]).

Upvotes: 1

Somraj Chowdhury
Somraj Chowdhury

Reputation: 1043

This is what is means:

nameMap[1] will return a str type object

print(nameMap[1]) will return a NoneType object

Here is the supporting code:

When in confusion, use the type() method to check the type of a value.

>>> nameMap = {1: "Bob", 2: "Pete", 3: "Ben", 4: "Bud", 5: "Russ"}

>>> nameMap[1]
'Bob'
>>> type(nameMap[1])
<class 'str'>

>>> print(nameMap[1])
Bob
>>> type(print(nameMap[1]))
Bob
<class 'NoneType'>

Upvotes: 2

abhiarora
abhiarora

Reputation: 10430

in order to obtain a value, the out puts are slightly different when using print(nameMap[1]) and nameMap[1]. Can you explain what is exactly going here. Thank you.

I think you mean the difference between "when you try to print the value of a variable using explicit print call" vs "without using print by typing the variable name directly over the interpreter".

I have tired your code with my interpreter:

Python 3.7.5 (default, Nov 20 2019, 09:21:52) 
[GCC 9.2.1 20191008] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> nameMap={1: "Bob", 2: "Pete", 3: "Ben", 4: "Bud", 5:  "Russ"}
>>> print(nameMap[1])
Bob
>>> nameMap[1]
'Bob'
>>>

My guess is that the difference in printing is due to the difference in the __repr__ and __str__ method of the class.

print(variable) equals to print(str(variable))

whereas

variable equals to print(repr(variable)).

Try this too:

>>> print(nameMap[1])
Bob
>>> nameMap[1]
'Bob'
>>> print(repr(nameMap[1]))
'Bob'
>>>

Upvotes: 1

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