Python:Control structures

Most flow control is standard. Indentation defines the code block to execute. You must be strich, all indents must be the same in a block, amix of spaces and tab is not allowed (unless each line uses the same mix)..........

if expression:
    block
else:
    otherblock

pass

No operation, use e.g. to avoid negative tests

Exception handling

To catch all exceptions (not wise)

try:
    block
except:
    blockifexceptionisthrown

You better only catch the exceptions you expect. You can choose from the available exceptions [1]

except NameError

The variable does not exist