Page 252 - Ai_V1.0_Class9
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Each element can be accessed by using:
listname[index number]
Commands Output
print(L1[0]) P
print(L1[3]) H
print(L1[-3]) H
print(L1[-1]) N
print(L1) #print complete list ['P', 'Y', 'T', 'H', 'O', 'N']
print(L1[0], L1[4]) P O
Traversing a List
Traversing means visiting each element and processing it as required by a program. We use a loop to traverse a
list. There are different ways of visit each element as shown below:
Commands Output
L1=['P', 'Y', 'T', 'H', 'O', 'N'] P ! Y ! T ! H ! O ! N !
for eachvalue in L1:
print(eachvalue, end="!")
L1=['P', 'Y', 'T', 'H', 'O', 'N'] P ! Y ! T ! H ! O ! N !
for indexno in range(len(L1)):
print(L1[indexno],end="!")
#The above code is equivalent to: P ! Y ! T ! H ! O ! N !
L1=['P', 'Y', 'T', 'H', 'O', 'N']
print(L1[0], L1[1], L1[2], L1[3], L1[4], L1[5],
sep="!",end="!")
#To print the index number of each element in a list 0 ! 1 ! 2 ! 3 ! 4 ! 5 !
L1=['P', 'Y', 'T', 'H', 'O', 'N']
for indexno in range(len(L1)):
print(indexno,end="!")
Using + Operator with List
The + operator is used to concatenate the list with another list. Remember that both the operands on either side
of the + operator have to be a list only otherwise it gives an error. For example,
Commands Output
A = [1, 2, 3] [1, 2, 3, 4, 5, 6]
B = [4, 5, 6]
C = A + B
print(C)
A = [1, 2, 3] [4, 5, 6, 1, 2, 3]
B = [4, 5, 6]
B += A
print(B)
250 Artificial Intelligence Play (Ver 1.0)-IX

