PYTHON PROGRAMMING (2010)
Basic Operators
The basic operators for python language are as follows.
· Arithmetic Operators
· Comparison Operators
· Logical Operators
· Membership Operators
· Identity Operators
Arithmetic operators
Addition- Adds values on either side of the operator. Represented by ‘+’.
Example
a + b will give 30.
Subtraction- This subtracts right hand operand from left hand operand. Represented by ‘-‘.
Example
a - b will give -10.
Multiplication- Multiplies values on either side of the operator. Represented by ‘*‘.
Example
a * b will give 200.
Division- Divides left hand operand by right hand operand. Represented by ‘/’.
Example
b / a will give 2.
Modulus- Divides left hand operand by right hand operand and returns remainder. It is represented by ‘%’.
Example
b % a will give 0.
Exponent- It performs power calculation on operators. It is represented by ‘**’.
Example
a**b will give 10 to the power 20.
Floor Division- This is a kind of division of operands where the result will be the quotient where the digits after the decimal point are deducted.
Example
9//2 is equal to 4 and
9.0//2.0 is equal to
4.0.
Program
#!/usr/bin/python
a = 21
b = 10
c = 0
c = a + b
print "Line 1 - Value of c is ", c
c = a - b
print "Line 2 - Value of c is ", c
c = a * b
print "Line 3 - Value of c is ", c
c = a / b
print "Line 4 - Value of c is ", c
c = a % b
print "Line 5 - Value of c is ", c
a = 2
b = 3
c = a**b
print "Line 6 - Value of c is ", c
a = 10
b = 5
c = a//b
print "Line 7 - Value of c is ", c
Output
Line 1 - Value of c is 31
Line 2 - Value of c is 11
Line 3 - Value of c is 210
Line 4 - Value of c is 2
Line 5 - Value of c is 1
Line 6 - Value of c is 8
Line 7 - Value of c is 2
Comparison operator
==- Checks if the value of two operands is equal or not, if yes then only the condition becomes true.
Example
(a == b) is not true.
!=- Checks if the value of two operands is equal or not, if values are not equal. Then only the condition becomes true.
Example
(a != b) is true.
<>- Checks whether the value of two operands is same or not, if values are not same then only condition becomes true.
Example
(a <> b) is true.
>=- Checks if the value of left operand is larger than or equal to the value of right operand, if yes then condition becomes true.
Example
(a >= b) is not true.
<=- Checks if the value of left operand is smaller than or equal to the value of right operand, if yes then condition becomes true.
Example
(a <= b) is true.
Program
#!/usr/bin/python
a = 21
b = 10
c = 0
if ( a == b ):
print "Line 1 - a is equal to b"
else:
print "Line 1 - a is not equal to b"
if ( a != b ):
print "Line 2 - a is not equal to b"
else:
print "Line 2 - a is equal to b"
if ( a <> b ):
print "Line 3 - a is not equal to b"
else:
print "Line 3 - a is equal to b"
if ( a < b ):
print "Line 4 - a is less than b"
else:
print "Line 4 - a is not less than b"
if ( a > b ):
print "Line 5 - a is greater than b"
else:
print "Line 5 - a is not greater than b"
a = 5;
b = 20;
if ( a <= b ):
print "Line 6 - a is either less than or equal to b"
else:
print "Line 6 - a is neither less than nor equal to b"
if ( b >= a ):
print "Line 7 - b is either greater than or equal to b"
else:
print "Line 7 - b is neither greater than nor equal to b"
Output
Line 1 - a is not equal to b
Line 2 - a is not equal to b
Line 3 - a is not equal to b
Line 4 - a is not less than b
Line 5 - a is greater than b
Line 6 - a is either less than or equal to b
Line 7 - b is either greater than or equal to b.
Logical operator
And- Termed Logical AND operator, both the values are true,therefore the condition becomes true.
Example
(a and b) is true.
Or- Termed Logical OR Operator any of the two values are non zero and then the condition becomes true.
Example
(a or b) is true.
Not- Termed as Logical NOT Operator that function is to reverse the logical situation of its operand.
Example
not(a and b) is false.
Membership operator
In- Its evaluation is true only if it finds a particular variable in the specified sequence and falseif not.
Example
x in y, here in results in a 1 if x is a member of sequence y.
Not in- If it’s evaluates is true and it does not finds a variable in the specified sequence and false if not.
Example
x not in y, here not in results in a 1 if x is not a member of sequence y.
Identify operator
Is- Its evaluation is true if the variables on either side of the operator do point to the same object and falseif not.
Example
x is y, here is results in 1 if id(x) equals id(y).
Is not- its evaluation is false if the variables on either side of the given operator points to the same object and true if not.
Example
x is not y, here is not results in 1 if id(x) is not equal to id(y).
Program
#!/usr/bin/python
a = 20
b = 20
if ( a is b ):
print "Line 1 - a and b have same identity"
else:
print "Line 1 - a and b do not have same identity"
if ( id(a) == id(b) ):
print "Line 2 - a and b have same identity"
else:
print "Line 2 - a and b do not have same identity"
b = 30
if ( a is b ):
print "Line 3 - a and b have same identity"
else:
print "Line 3 - a and b do not have same identity"
if ( a is not b ):
print "Line 4 - a and b do not have same identity"
else:
print "Line 4 - a and b have same identity"
Output
Line 1 - a and b have same identity
Line 2 - a and b have same identity
Line 3 - a and b do not have same identity
Line 4 - a and b do not have same identity.
