🐍 Basic Error Messages in Python

When learning Python (programming language), you will encounter error messages. These are Python’s way of telling you that something is wrong with your code. Understanding them is important for debugging and fixing mistakes.

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🔹 1️⃣ SyntaxError

Occurs when Python cannot understand your code because it violates the rules of Python syntax.

Example:

print("Hello World"

Output:

SyntaxError: unexpected EOF while parsing

Fix: Ensure parentheses and quotation marks are properly closed.

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🔹 2️⃣ NameError

Occurs when you try to use a variable or function that has not been defined.

Example:

print(age)

Output:

NameError: name 'age' is not defined

Fix: Define the variable before using it:

age = 20
print(age)

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🔹 3️⃣ TypeError

Occurs when you perform an operation on incompatible types.

Example:

x = 5
y = "10"
print(x + y)

Output:

TypeError: unsupported operand type(s) for +: 'int' and 'str'

Fix: Convert types so they are compatible:

print(x + int(y))

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🔹 4️⃣ ValueError

Occurs when a function receives a valid type but invalid value.

Example:

num = int("hello")

Output:

ValueError: invalid literal for int() with base 10: 'hello'

Fix: Ensure the value can be converted properly:

num = int("123")

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🔹 5️⃣ IndexError

Occurs when you try to access an index that doesn’t exist in a list, tuple, or string.

Example:

fruits = ["apple", "banana"]
print(fruits[2])

Output:

IndexError: list index out of range

Fix: Check the length of the list before accessing elements.

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🔹 6️⃣ KeyError

Occurs when you try to access a key that doesn’t exist in a dictionary.

Example:

student = {"name": "Rahul", "age": 21}
print(student["grade"])

Output:

KeyError: 'grade'

Fix: Use a valid key or check with get():

print(student.get("grade", "Not Found"))

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🔹 7️⃣ AttributeError

Occurs when you try to use a method or attribute that doesn’t exist for a data type.

Example:

x = 5
x.append(3)

Output:

AttributeError: 'int' object has no attribute 'append'

Fix: Use the method on the correct data type:

nums = [5]
nums.append(3)

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⭐ Key Points

• Read error messages carefully, they tell you what and where the problem is.
• Common errors for beginners: SyntaxError, NameError, TypeError, ValueError, IndexError, KeyError, AttributeError.
• Debugging involves checking variable names, data types, and syntax.