What is "if not" in python?

[Person009]

For example what does the third line mean?

contents = open("file.dat").read()
for line in contents.split("*"):
  if not line: continue  # Remove initial empty string.
  line = line.strip()   # Remove whitespace from beginning/end of lines.
  items = line.split("-")
  print items[0], ":", " ".join(items[1:])
 

[Smygis]

it means that if line does not contain anything it continues to the next iteration of the loop

[eGrove Systems]

'If not' is a condition which is used to check whether the list is empty or not
for example:

         lister=[]
         if not lister:
                print "list is in empty"

[maya29988]

if not <condition> in python is equal to if (!<condition>) in c.

[Hellstorm6X]

It's really an easy concept.