# Chapter 4: Expressions¶

## Example upc.c, Page Number-57¶

In [1]:
def main():
#input from user
d=int(raw_input("Enter the first (single) digit: "))
firstfive= raw_input("Enter first group of five digits")
list1=list(firstfive)
i1=list1[0]
i2=list1[1]
i3=list1[2]
i4=list1[3]
i5=list1[4]
secondfive= raw_input("Enter second group of five digits")
list2=list(firstfive)
j1=list2[0]
j2=list2[1]
j3=list2[2]
j4=list2[3]
j5=list2[4]
first_sum=d+int(i2)+int(i4)+int(j1)+int(j3)+int(j5)
second_sum=int(i1)+int(i3)+int(i5)+int(j2)+int(j4)
total=3*first_sum+second_sum
s=9-((total - 1) % 10)
print "Check digit: %d" % s #print result

if  __name__=='__main__':
main()

Enter the first (single) digit: 0
Enter first group of five digits13800
Enter second group of five digits15713
Check digit: 2


## Example on Page number-59¶

In [2]:
#variable declaration
i = 1
#k = l + (j=i)
j=i
k=1+j
print "%d %d %d" % (i,j,k)  #prints "1 1 2"

1 1 2


## Example on Page number-61¶

In [5]:
i=1 #variable declaration
i+=1
print "i is %d" % i #++i
print "i is %d" % i #i

i = 1
j=i+1
print "i is %d" % i #i++
print "i is %d" % j #i

i is 2
i is 2
i is 1
i is 2


## Example on Page number-62¶

In [6]:
i=1 #variable declaration
i-=1
print "i is %d" % i #--i
print "i is %d" % i #i

i = 1
j=i-1
print "i is %d" % i #i--
print "i is %d" % j #i

i is 0
i is 0
i is 1
i is 0

In [ ]: