1.4 except:

Python has the except: clause, which catches all exceptions. Since every error in Python raises an exception, this makes many programming errors look like runtime problems, and hinders the debugging process.

The following code shows a great example:

try:
    foo = opne("file") # misspelled "open"
except:
    sys.exit("could not open file!")

The second line triggers a NameError which is caught by the except clause. The program will exit, and you will have no idea that this has nothing to do with the readability of "file".

There are some situations in which the except: clause is useful: for example, in a framework when running callbacks, it is good not to let any callback disturb the framework.