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Lets assume i have a file named 'student.csv'.But in my python,I have mistakenly passed 'student1.csv' as file input,which does not exist.How to handle this exception to stop the execution further.

Saravanan Selvam
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    Just letting the program crash with a FileNotFoundError seems like a perfectly fine way to handle the exception. Execution of the program is stopped, exactly as desired; and anyone reading the stack trace knows exactly what the problem is. – Kevin Jul 12 '19 at 13:11
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    use try -except block – Vinay Hegde Jul 12 '19 at 13:13
  • Possible duplicate of [File Open Function with Try & Except Python 2.7.1](https://stackoverflow.com/questions/8380006/file-open-function-with-try-except-python-2-7-1) – Dipesh Bajgain Jul 12 '19 at 13:13
  • @Kevin: Sure, 'cause nothing breeds confidence in an end user than seeing a stack trace. – Scott Hunter Jul 12 '19 at 13:13
  • @Kevin, for example, `open(nonexistent_file, 'w')` doesn't raise an exception, but creating a new file may not be desired, so this behavior may be considered an "exception". It's hard to tell what "exception" means in this context because unhandled exceptions _do_ stop the program's execution, which somehow isn't the case here – ForceBru Jul 12 '19 at 13:15
  • I am getting TypeError: 'NoneType' object is not iterable How to handle this exception – Saravanan Selvam Jul 12 '19 at 13:17
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    @ScottHunter Don't think of it as user-hostile design; think of it as encouraging the user to learn the fundamentals of programming. Having to diagnose uncaught exceptions builds character ;-) – Kevin Jul 12 '19 at 13:18

2 Answers2

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Here is a working example, if the file is not found it will throw and FileNotFoundError exception

try:
    f = open('student.csv')
except FileNotFoundError:
    print('File does not exist')
finally:
    f.close()
    print("File Closed")

Another Way:

try:
    with open("student.csv") as f:
        print("I will do some Magic with this")
except FileNotFoundError:
    print('File does not exist')

Also If you dont want custom error message you can just use

with open("student.csv") as f:
       print("I will do some Magic with this")

If the file does not exist you will still get an FileNotFoundErorr

example: 

FileNotFoundError: [Errno 2] No such file or directory: 'student1.csv'
AutoTester213
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1

USe exception handling:-

try:
    file = open('student.csv')
except Exception as e:
    print('File not found. Check the name of file.')
Rahul charan
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