There are some common exceptions in python. These exceptions are usually raised in different programs. These may raise by the programmer explicitly, or the python interpreter can raise these type of exceptions implicitly. Some of these exceptions are −
Exception AssertionError
The AssertionError may raise, when an assert statement fails. In python there are some, we can also set some assert statement in our code. The assert statement always must be true. if the condition fails, it will raise AssertionError.
Example Code
class MyClass:
def __init__(self, x):
self.x = x
assert self.x > 50
myObj = MyClass(5)
Output
---------------------------------------------------------------------------
AssertionError Traceback (most recent call last)
<ipython-input-21-71785acdf821> in <module>()
4 assert self.x > 50
5
----> 6 myObj = MyClass(5)
<ipython-input-21-71785acdf821> in __init__(self, x)
2 def __init__(self, x):
3 self.x = x
----> 4 assert self.x > 50
5
6 myObj = MyClass(5)
AssertionError:
Exception AttributeError
The attribute error may raise, when we will try to access some attribute of a class, but it is not present in it.
Example Code
class point:
def __init__(self, x=0, y=0):
self.x = x
self.y = y
def getpoint(self):
print('x= ' + str(self.x))
print('y= ' + str(self.y))
print('z= ' + str(self.z))
pt = point(10, 20)
pt.getpoint()
Output
x= 10
y= 20
---------------------------------------------------------------------------
AttributeError Traceback (most recent call last)
<ipython-input-15-f64eb52b2192> in <module>()
10
11 pt = point(10, 20)
---> 12 pt.getpoint()
<ipython-input-15-f64eb52b2192> in getpoint(self)
7 print('x= ' + str(self.x))
8 print('y= ' + str(self.y))
----> 9 print('z= ' + str(self.z))
10
11 pt = point(10, 20)
AttributeError: 'point' object has no attribute 'z'
Exception ImportError
The ImportError may occur when the import statement is facing some problem to import some module. It can also be raised, when the package name to a from statement is correct, but there is no module found as specified name.
Example Code
from math import abcd def __init__(self, x=0, y=0):
Output
--------------------------------------------------------------------------- ImportError Traceback (most recent call last) <ipython-input-23-ff4519a07c77> in <module>() ----> 1 from math import abcd ImportError: cannot import name 'abcd'
Exception ModuleNotFoundError
It is a subclass of the ImportError. When a module is not located, this error may raise. It can also be raised when None is found in sys.modules.
Example Code
import abcd
Output
--------------------------------------------------------------------------- ModuleNotFoundError Traceback (most recent call last) <ipython-input-24-7b45aaa048eb> in <module>() ----> 1 import abcd ModuleNotFoundError: No module named 'abcd'
Exception IndexError
The index error may raise when the subscript of a sequence (List, Tuple, Set etc) is out of range.
Example Code
myList = [10, 20, 30, 40] print(str(myList[5]))
Output
---------------------------------------------------------------------------
IndexError Traceback (most recent call last)
<ipython-input-29-a86bd85b04c9> in <module>()
1 myList = [10, 20, 30, 40]
----> 2 print(str(myList[5]))
IndexError: list index out of range
Exception RecursionError
The RecursionError is a runtime error. When the maximum recursion depth is exceeded, then it will raised.
Example Code
def myFunction(): myFunction() myFunction()
Output
---------------------------------------------------------------------------
RecursionError Traceback (most recent call last)
<ipython-input-39-8a59e0fb982f> in <module>()
2 myFunction()
3
----> 4 myFunction()
<ipython-input-39-8a59e0fb982f> in myFunction()
1 def myFunction():
----> 2 myFunction()
3
4 myFunction()
... last 1 frames repeated, from the frame below ...
<ipython-input-39-8a59e0fb982f> in myFunction()
1 def myFunction():
----> 2 myFunction()
3
4 myFunction()
RecursionError: maximum recursion depth exceeded
Exception StopIteration
In python, we can get the StopIteration error by the inbuilt method called next(). When one iterator has no further element, then the next() method will raise the StopIteration error.
Example Code
myList = [10, 20, 30, 40] myIter = iter(myList) while True: print(next(myIter))
Output
10
20
30
40
---------------------------------------------------------------------------
StopIteration Traceback (most recent call last)
<ipython-input-42-e608e2162645> in <module>()
2 myIter = iter(myList)
3 while True:
----> 4 print(next(myIter))
StopIteration:
Exception IndentationError
When there are some invalid indentation in the python code, it will raise this kind of errors. It inherits the SyntaxError class of python.
Example Code
for i in range(10):
print("The value of i: " + str(i))
Output
File "<ipython-input-44-d436d50bbdc8>", line 2
print("The value of i: " + str(i))
^
IndentationError: expected an indented block
Exception TypeError
The TypeError may occur when an operation is performed on an object of inappropriate type. For example, if we provide a floating point number in array index, it will return a TypeError.
Example Code
muList = [10, 20, 30, 40] print(myList[1.25])
Output
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-46-e0a2a05cd4d4> in <module>()
1 muList = [10, 20, 30, 40]
----> 2 print(myList[1.25])
TypeError: list indices must be integers or slices, not float
Exception ZeroDivisionError
When there is a situation where the denominator is 0 (zero) for a division problem, it will raise ZeroDivisionError.
Example Code
print(5/0)
Output
--------------------------------------------------------------------------- ZeroDivisionError Traceback (most recent call last) <ipython-input-48-fad870a50e27> in <module>() ----> 1 print(5/0) ZeroDivisionError: division by zero