Python None vs Null vs is None vs == Comparison Explained

Hello, this is BlockDMask.

Today, let’s clearly explain some of the most confusing concepts in Python: None, null, empty string (""), 0, False, [], {}, and the difference between the comparison operators is and ==.

Many beginners get confused when to use is None vs == None, and how Python treats different "empty" values.
Let’s break it down step-by-step with simple and practical examples.

Table of Contents


1. Python null is None

response = None
print(response)

Output:

None

→ In Python, there’s no null. Instead, we use None to represent "no value" or "nothing exists".


2. Difference: None, 0, "", [], {}, False

Python considers all of these as False in boolean checks, but they are very different objects:

Value Meaning Boolean Evaluation Type
NoneNo valueFalseNoneType
0ZeroFalseint
""Empty stringFalsestr
[]Empty listFalselist
{}Empty dictionaryFalsedict
FalseBoolean FalseFalsebool

→ They all evaluate as False in condition checks but they are completely different types under the hood.


3. is vs == comparison

first = None
second = None

print(first == second)
print(first is second)

Output:

True
True

→ == checks if values are equal. is checks if both refer to the same object in memory. Since None is a singleton object, both are True here.


score = 0
flag = False

print(score == flag)
print(score is flag)

Output:

True
False

→ Although both behave as False in conditions, their types are different (int vs bool).


x = []
y = []

print(x == y)
print(x is y)

Output:

True
False

→ Two empty lists have equal content (== True) but they are different objects in memory (is False).


4. How to properly check for None

data = None

if data is None:
    print("No data received.")

Output:

No data received.

→ Always use is None to check for None. This is recommended in PEP8 (Python’s style guide).


5. Using None as default argument in functions

def send_message(user=None):
    if user is None:
        print("No recipient specified.")
    else:
        print(f"Sending message to {user}")

send_message()
send_message("BlockDMask")

Output:

No recipient specified.
Sending message to BlockDMask

→ None is often used as a default parameter to check whether an argument was passed.


6. Difference: None vs Empty String

def check_value(val):
    if val is None:
        print("Value is None.")
    elif val == "":
        print("Value is an empty string.")
    else:
        print("Value exists:", val)

check_value(None)
check_value("")
check_value("Python Rocks")

Output:

Value is None.
Value is an empty string.
Value exists: Python Rocks

→ None and "" are different and should be handled separately in conditionals.


7. Summary Table

Concept Meaning Example Usage
NoneNo valueif x is None
""Empty stringif x == ""
0Zeroif x == 0
==Value comparisonif a == b
isObject identityif a is b
is NoneCheck for None(Recommended)

That’s a full explanation of None, null, is None, and == differences in Python.
Thanks for reading!

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