Exception Handling

 raise error_name("message")

ERRORS:

NameError-undefined variable,mistype in variable/function name or name not enclosed in quotes

TypeError- related to data types problems [eg. str doesn't work on int]

ValueError-when a function gets wrong data type as input

ZeroDivisinError

AttributeError-using wrong methods or returning none/no return statement

KeyError-dict

IndexError

IOError-file not found

EOFError - end of file error

FileNotFoundError

IndentationError

SYNTAX:

try:

except error1:runs if try has error1

except error2:runs if try has error2

Multiple exceptions can be specified in a except block. Eg

except error1, error2 :

else:runs if no error1

finally:always run, even if try block has return or break in it

Python debugger module == pdb

command prompt-$python-mpdbmycode.py

pdb COMMANDS:

l(lsit)-shows current position

n(next)-next line excluding function

s(step)-next line including function

r(return)-steps to end of current executing function

c(continue)-executes code

q(quit) enter key/ctrl+d

?(help)

FUNCTIONS:

pdb.set_trace()-creates a breakpoint

pdb.post_mortem(traceback)-enter post-morten debugging of given traceback object

pdb.pm()-enter post-morten debugging of given traceback object found in sys.last_traceback

pdb.run(statement)

pdb.runeval(expression)

pdb.runcall(function[arguments])


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