Python try-except blocks are used for exception handling or error handling. With the use of try-except block in your program, you can allow your program to continue or terminate at a point or show messages.
If an error occurred in the program, then the try block will pass to except block. In addition, you can also use a finally block to execute whether an exception occurs or not.
Important terms in Python try-except block.
trya block of code to the probability of error.
exceptblock lets you handle the error.
- else block if no exception in the program.
- finally regardless of the result of the try- and except blocks, this code always executes.
Simple syntax of try except block.
Basic Syntax : try: // Code except: // Code
Python try except Example
This is a simple sample of try-except block in python. If the arithmetic operation will be done then nothing print otherwise the output will be an error message.
try: print(0 / 0) except: print("An exception occurred")
Output: An exception occurred
Example try except a print error in python
An example of how to python “except exception as e” and print error in console.
try: print(1 / 0) except Exception as e: print(e)
Output: division by zero
Example try except Else
You can use python try except else to execute a block of code in if no error raised.
try: print(1 / 1) except Exception as e: print(e) else: print("No Error")
Example try-except Finally in Python
Finally, code of block always execute on error or not.
try: print(1 / 0) except Exception as e: print(e) else: print("No Error") finally: print("Always print finally python code")
Output: division by zero
Always print finally python code
QA: What is the use of finally block in Python try-except error handling?
It can be an interview question.
Finally, the block can be useful to close objects and clean up resources, like close a writable file or database.
Like this example of writing a file in python.
case: if file existing or creates it.
try: mfile = open("textfile.txt", "w") mfile.write("EyeHunts") except Exception as ex: print(ex) finally: mfile.close() print('File Closed')
Output: File Closed
case: if file not existing
try: mfile = open("textfile.txt") mfile.write("EyeHunts") except Exception as ex: print(ex) finally: print('File Closed call') mfile.close()
Note: This tutorial is explained about exception handling blocks and how to use them. You must read about details about exception handling in this tutorial – Python exception Handling | Error Handling
As another language like Java using a try-catch for exception handling. If you are looking for a python try-catch, then you will not find it. Python has a try-except instead of try-catch exception handling.
Do comment if you have any doubts and suggestion on this tutorial.
Note: This example (Project) is developed in PyCharm 2018.2 (Community Edition)
JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o
All examples are in try except python 3, so it may change its different from python 2 or upgraded versions.
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