Built in functions: next, bool

next(iterator)

Python built-in function next is used to retrieve next item from an iterator, if it reaches iterator end built-in exception StopIteration is raised. 

Example:

list1 = [23, True, 'yes']

myIterator = iter(list1)

#

item = next(myIterator)

print(f"First item is: {item}")

#

item = next(myIterator)

print(f"Item is: {item}")

#

item = next(myIterator)

print(f"Last item is: {item}")

item = next(myIterator)


#Output

First item is: 23

Item is: True

Last item is: yes

Traceback (most recent call last):

  File "test.py", line 9, in <module>

    item = next(myIterator)

StopIteration

In this example we create iterator myIterator from list1. Then we run next funtion trice using item = next(myIterator) and print item with a f string. myIterator have 3 items, after running trice next function we are at the end of it, once try to run the fourth time next function, StopIteration built-in exception is raised. 


class bool(x=False)

The method return a boolean value based on standard "truth testing procedure". Basically this procedure will return True if argument is a number (excepting 0), a string or True itself. It will return False if argument is False, 0 or None, empty. "Truth testing procedure" in python area is comprehensive described here


Examples:

myarg1=12

print(bool(myarg1))

# output: True


myarg2='string123'

print(bool(myarg2))

# output: True


myarg3=True

print(bool(myarg3))

# output: True


myarg4=False

print(bool(myarg4))

# output: False


myarg5=0

print(bool(myarg5))

# output: False


myarg6=None

print(bool(myarg6))

# output: False


print(bool())

# output: False