Python Error Handling Files
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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 errors, are perhaps python exception message the most common kind of complaint you get while you are still learning Python: syntax for generic except clause in python >>> while True print('Hello world') File "
Python Print Exception
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 error when an attempt is made to execute it. Errors python try except else 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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Name Of Errors In Python
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An Exception Can Be In Python
Overflow is a community of 6.2 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up What is a good way to handle exceptions when trying to https://docs.python.org/3/tutorial/errors.html read a file in python? up vote 9 down vote favorite 2 I want to read a .csv file in python. I don't know if the file exists. My current solution is below. It feels sloppy to me because the two separate exception tests are awkwardly juxtaposed. Is there prettier way to do it? import csv fName = "aFile.csv" try: with open(fName, 'rb') as f: reader = csv.reader(f) http://stackoverflow.com/questions/5627425/what-is-a-good-way-to-handle-exceptions-when-trying-to-read-a-file-in-python for row in reader: pass #do stuff here except IOError: print "Could not read file:", fName python file-io exception-handling share|improve this question edited Apr 11 '11 at 21:08 asked Apr 11 '11 at 20:51 CharlesHolbrow 1,05431621 add a comment| 4 Answers 4 active oldest votes up vote 6 down vote accepted I guess I misunderstood what was being asked. Re-re-reading, it looks like Tim's answer is what you want. Let me just add this, however: if you want to catch an exception from open, then open has to be wrapped in a try. If the call to open is in the header of a with, then the with has to be in a try to catch the exception. There's no way around that. So the answer is either: "Tim's way" or "No, you're doing it correctly.". Previous unhelpful answer to which all the comments refer: import os if os.path.exists(fName): with open(fName, 'rb') as f: try: # do stuff except : # whatever reader errors you care about # handle error share|improve this answer edited Apr 11 '11 at 21:23 answered Apr 11 '11 at 20:55 Josh Caswell 52.6k11103152 5 Just because a file exists doesn't mean that you can read it! –Gab
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