In this tutorial, we will discuss what are python exception and when and why they occur. There are many kinds of error in python and one of the most common error is syntax error this error occurs due to some misalignment of syntax and the python interpreter could not understand what that syntax wants to say.
Python Exception
Example:
for i in range()
print("i")
#Output
SyntaxError: invalid syntax
Behind the code:
In the above example we got an error because we did not put a colon(:) after the range() so the interpreter get confused with the statement and throw an error.
Exception:
Sometimes we see that our python code gets executed and the interpreter does not collect any error from the code and suppose in that code we ask a user to enter an integer value, but the user enters a string instead, this could cause an error this kind of error known as Exception.
An exception can be defined as those errors occur in the program during the runtime or by some unexpected user input.
Some most common Exception are FileNotFoundError, ZeroDivisionError, ValueError and ImportError.
Example:
integer = int(input("Please enter an Integer value:"))
#Output
Please enter an Integer value: techgeekbuzz ValueError: invalid literal for int() with base 10: 'techgeekbuzz'
Behind the code:
In the above code, the programme asked for an integer value but we provided a string, this causes a runtime error.
Python Built-In exception:
There are many built-in Exception in python that can raise an error. We can see all the built-in exception using the locals() built-in function
Syntax:
locals()[‘__builtins__’]
Built-in Python Exception:
| Exceptions | Details |
| AssertionError | Due to failure of assert statement |
| AttributeError | Occur due to an illegal number of attribute pass |
| EOFError | Due to the input() function |
| FloatingPointError | Due to floating point |
| GeneratorExit | Due to generator’s close() method. |
| ImportError | When there is no such import module |
| IndexError | Out of range index called |
| KeyError | Unknown key passed along a dictionary. |
| KeyboardInterrupt | When user enter ctrl+c |
| MemoryError | Due to out of memory |
| NameError | When such a variable is not defined. |
| NotImplementedError | Due to the abstract method |
| OSError | System-related error. |
| OverflowError | When an arithmetic value is out of range |
| ReferenceError | Due to weak reference proxy |
| RuntimeError | Error during runtime |
| StopIteration | When there is no element left and we call next() |
| SyntaxError | Due to illegal syntax |
| IndentationError | Due to illegal indentation |
| TabError | Due to illegal indentation |
| SystemError | Internal error |
| SystemExit | Due to exit programme statement sys.exit() |
| TypeError | When two different data type print together |
| UnboundLocalError | When there is no such local variable. |
| UnicodeError | Encoding and decoding error |
| ValueError | Due to incorrect value pass in function argument |
| ZeroDivisionError | When any number divided by 0 |