PYTHON PROGRAMMING (2010)
Decision making of Python
· Decision making is one of the important aspects of any programming languages.
· Similarly it goes with the python the various structures are as follows.
Flow diagram
· In this programming language it assumes non-zero and non-null value as true.
· But if it is either zero or null it is assumed as false.
Following are the three decision making statement.
· If statement.
· If else statement.
· Nested if statement.
If statement
· Contains logical expression.
· Utilizes these expressions and converts them into a result after comparison.
Syntax
If expression:
Statement
If flow table
Program
#!/usr/bin/python
var1 = 100
if var1:
print "1 - Got a true expression value"
print var1
var2 = 0
if var2:
print "2 - Got a true expression value"
print var2
print "Good bye!"
Output
1 - Got a true expression value
100
Good bye!
If else statement
· If and else are combined.
· Else provide an option to the if statement.
Syntax
if expression:
statement(s)
else:
statement(s)
If else flow table
Program
#!/usr/bin/python
var1 = 100
if var1:
print "1 - Got a true expression value"
print var1
else:
print "1 - Got a false expression value"
print var1
var2 = 0
if var2:
print "2 - Got a true expression value"
print var2
else:
print "2 - Got a false expression value"
print var2
print "Good bye!".
Output
1 - Got a true expression value
100
2 - Got a false expression value
0
Good bye!
Nested if statement
· It is having various conditions one by one in sequence.
· It’s used to resolve one condition after one.
Syntax
if expression1:
statement(s)
if expression2:
statement(s)
elif expression3:
statement(s)
else
statement(s)
elif expression4:
statement(s)
else:
statement(s).
Program
#!/usr/bin/python
var = 100
if var < 200:
print "Expression value is less than 200"
if var == 150:
print "Which is 150"
elif var == 100:
print "Which is 100"
elif var == 50:
print "Which is 50"
elif var < 50:
print "Expression value is less than 50"
print "Could not find true expression"
print "Good by!".
Output
Expression value is less than 200
Which is 100
Good bye!
