1.Conditions 

-Python uses boolean variables to evaluate condiitions.

-Like True / False.

- "==" means "equal"?

- "!= " means "not equal" ?

x = 2 
print(x == 2)
print(x == 3)
print(x < 3)//print True / False / True

-Boolean operators -> "and " / "or"

-The "and" and "or" boolean operators allow building complex boolean expressions.

name = "John"
age = 23
if name == "John" and age == 23:print("Your name is John, and your age is 23.")
if name == "John" or name == "Rick":print("Your name is either John or Rick")

-The "in" operator

-The "in" operator could be used to check if a specified object exists within an iterable object container, such as a list

name = "John"
if name in ["John","Rick"]print("")

-The "is" operator

-This operator does not match the values of the variables, but the instances themselves.

x = [1,2,3]
y = [1,2,3]
print(x == y) // True
print(x is y) // False

-The "not" operator

-Using "not" before a boolean expression inverts it

print(not False) // True
print((not False) == (False)) //False

2.Loops

-As we know , we only have two main types of loops in Python ,for ans while.

-The "for" loop

-For loops iterate over a given sequence.

primes = [2,3,5,7]
for prime in primes:print(prime)

-Using "range" or "xrange" to iterate over a sequence of numbers. The difference between range and xrange is that the range function returens a new list with numbers of that specified range, whereas xrange returns an iterator, which is more efficient.(While in Python3 , the range function acts just like xrange)

numbers = [1,2,3,4]
for i in range(len(numbers)):print(numbers[I])//print out [1,2,3,4]
for x in range(3,6):print(x)//print out 3 4 5

-The "while" loops

-While loops repeat as long as a certain boolean condition is met.

count = 0
while count < 5:print(count)count += 1 // which equals count = count + 1 

-"break" and "continue" statements

-Break is used to exit a for loop or a while loop, whereas continue is used to skip the current block, and return to the "for" or "while"statement.

count = 0 
while True:print(count)count += 1if count >= 5:breakfor x in range(10):if x % 2 == 0:continueprint(x)

-! We can use "else" clause for loops !

-When the loop condition of "for" or "while" statement fails then code part in "else" is executed.If break statement is executed inside for loop then the "else" part is skipped. 

count=0
while(count<5):print(count)count +=1
else:print("count value reached %d" %(count))# Prints out 1,2,3,4
for i in range(1, 10):if(i%5==0):breakprint(i)
else:print("this is not printed because for loop is terminated because of break but not due to fail in condition")