Integer Error Python
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you have probably seen some. There are (at least) two distinguishable kinds of errors: syntax errors and exceptions. 8.1. Syntax Errors¶ Syntax errors, also known as parsing python exception class errors, are perhaps the most common kind of complaint you get while you syntax for generic except clause in python are still learning Python: >>> while True print('Hello world') File "
Python Raise Custom Exception
least detected at) the token preceding the arrow: in the example, the error is detected at the function print(), since a colon (':') is missing before it. File name and line number are printed so you know where to look in case the input came from a script. 8.2. Exceptions¶ Even if a statement or expression is syntactically correct, it may cause an is nested try block possible in python error when an attempt is made to execute it. Errors detected during execution are called exceptions and are not unconditionally fatal: you will soon learn how to handle them in Python programs. Most exceptions are not handled by programs, however, and result in error messages as shown here: >>> 10 * (1/0) Traceback (most recent call last): File "
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Syntax For Raise Clause In Python
Sign up Python Error handling using integers as input up vote 3 down vote favorite Ive set up this program that checks the mark out of 100 for a test. If the user inputs less than 60 it should say fail https://docs.python.org/3/tutorial/errors.html if more than 59, pass. mark = int(input("Please enter the exam mark out of 100 ")) if mark < 60: print("\nFail") elif mark < 101: print("\nPass") else: print("\nThe mark is out of range") how do i get the program not to have errors if the user does not input the Integer. Please help, is there a quick solution that 14 year olds would understand? python integer share|improve this question asked Jul 11 '12 at 12:42 Tech484 162 Are you using http://stackoverflow.com/questions/11432913/python-error-handling-using-integers-as-input Python 3.x? –Levon Jul 11 '12 at 12:44 If you're using python 2, use raw_input instead of input. Then follow one of the answers below. –kojiro Jul 11 '12 at 12:46 If the user inputs less than 60 it should say fail if more than 59, pass. So what is the passing score? 59.5? :) –Burhan Khalid Jul 11 '12 at 12:47 add a comment| 2 Answers 2 active oldest votes up vote 4 down vote Save the input in a variable and convert to an integer separately: import sys i = input("Please enter the exam mark out of 100 ") try: mark = int(i) except ValueError: print('\nYou did not enter a valid integer') sys.exit(0) if mark < 60: print("\nFail") elif mark < 101: print("\nPass") else: print("\nThe mark is out of range") If it fails (i.e., you get a ValueError) then print a message and exit. You can explain (to a 14-year old) that int() needs a valid integer as input and it will raise a ValueError otherwise. That makes sense because only strings that contain an integer can be converted by int(). share|improve this answer answered Jul 11 '12 at 12:46 Simeon Visser 52.5k877105 add a comment| up vote 3 down vote try: mark = int(input("Please enter the exam mark out of 100 ")) except ValueError: print("\nPlease only use integers") share|improve this answer edited Jul 11 '12 at 14:50 answered Jul 11 '12 at 12:44 Rob Wagner 3,687721 3 "Che
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more about hiring developers or posting http://stackoverflow.com/questions/3501382/checking-whether-a-variable-is-an-integer-or-not ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the http://stackoverflow.com/questions/1265665/python-check-if-a-string-represents-an-int-without-using-try-except Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up Checking whether a variable is an integer or not up vote 412 down vote favorite 95 How do I check whether a variable is an integer? python share|improve this question edited Jun 16 '12 at 19:48 Masi 32.7k110335519 asked in python Aug 17 '10 at 10:15 Hulk 7,06336110174 1 possible duplicate of What's the canonical way to check for type in python? –S.Lott Aug 17 '10 at 10:53 1 @Hulk: You seem to be under the impression that type is the right way to do this. It is (almost certainly) not. –katrielalex Aug 17 '10 at 12:16 @katrielalex: if he had chosen my answer as the right one doesn't mean Hulk was under the impression you mention. There also clause in python is the ValueError exception way mentioned BEFORE the type(). –Jungle Hunter Aug 17 '10 at 13:37 2 @Hulk: No offense taken. But to be clear, the only way you can catch an exception (that I know of) is by using an except clause. I suggested you catch the TypeError exception. –Jungle Hunter Aug 17 '10 at 16:54 6 This question is ambiguous, and the answers are accordingly divided. Some are answering how to check the type of a variable (5→True, 5.0→ False), while others are answering how to check that the value is an integer (5→True, 5.0→True, Fraction(5,1)→True, 5.4→False). Maybe the question and answers should be split up accordingly? –endolith May 10 '13 at 14:39 | show 7 more comments 33 Answers 33 active oldest votes 1 2 next up vote 471 down vote accepted If you need to do this, do isinstance( , int ) unless you are in Python 2.x in which case you want isinstance( , ( int, long ) ) Do not use type. It is almost never the right answer in Python, since it blocks all the flexibility of polymorphism. For instance, if you subclass int, your new class should register as an int, which type will not do: class Spam( int ): pass x = Spam( 0 ) type( x ) == int # False isinstance( x, int ) # True This adheres to Python's strong polymorphism: you should allow any object that behaves like an int, ins
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up Python: Check if a string represents an int, Without using Try/Except? up vote 138 down vote favorite 22 Is there any way to tell whether a string represents an integer (e.g., '3', '-17' but not '3.14' or 'asfasfas') Without using a try/except mechanism? is_int('3.14') = False is_int('-7') = True python string integer share|improve this question edited Aug 19 '14 at 18:01 GEOCHET 16.4k156085 asked Aug 12 '09 at 11:46 Adam Matan 29.3k58176297 17 Why both trying to do this "the hard way?" What's wrong with try/except? –S.Lott Aug 12 '09 at 12:09 3 Yes, what's wrong with try/except? Better to ask for forgiveness than for permission. –mk12 Sep 14 '09 at 2:27 14 I would ask why should this simple thing require try/except? Exception system is a complex beast, but this is a simple problem. –Aivar Sep 23 '11 at 20:18 7 @Aivar stop spreading FUD. A single try/except block does not even approach "complex". –Triptych Feb 3 '12 at 20:21 12 It's not really FUD, though. You'd be effectively writing 4 lines of code, expecting something to blow up, catching that exception and doing your default, instead of using a one liner. –andersonvom Nov 12 '13 at 19:32 | show 1 more comment 13 Answers 13 active oldest votes up vote 137 down vote accepted If you're really just annoyed at using try/excepts all over the place, please just write a helper function: def RepresentsInt(s): try: int(s) return True except ValueError: return False >>> print RepresentsInt("+123") True >>> print RepresentsInt("10.0") False It's going to be WAY more code to exactly cover all the strings that Python considers integers. I say just be pythonic on this one. share|improve this answer answered Aug 12 '09 at 16:05 Triptych 111k24117152 35 So it's pythonic to solve simple problem with complex mechanism? There is an algorithm