10/9/13

Strings are sequences of characters



In [10]:

    
word = 'computer'
#print first letter of word
print word[0]
print word[1]
print word[7]
print word[-1]
print word[-2]
print word[1:5]
print word[3:-1]
print word[1:-2]
print word[3:]
print word[:4]









    



c
o
r
r
e
ompu
pute
omput
puter
comp



In [11]:

    
print "The length of word is", len(word)









    



The length of word is 8



In [12]:

    
word = raw_input("Please type a word: ")
print "The word you entered is", len(word), "characters long!"









    



Please type a word: fork
The word you entered is 4 characters long!



In [15]:

    
#take a string from the user
#print out each character individually
word = raw_input("Please give me a word: ")
count = len(word)
x = 0
while x < count:
    print word[x]
    x = x + 1









    



Please give me a word: iphone
i
p
h
o
n
e



In [17]:

    
word = raw_input("Please give me a word: ")
for character in word:
    print character









    



Please give me a word: iphone
i
p
h
o
n
e



In [19]:

    
word = raw_input("Please give me a word: ")
for character in word:
    print character
    if character == 'g':
        break









    



Please give me a word: goose
g

Strings are immutable!

You cannot change the value of a string.



In [20]:

    
word = 'fluffy'
word[0] = 'x'









    



---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-20-840d4977a1b7> in <module>()
      1 word = 'fluffy'
----> 2 word[0] = 'x'

TypeError: 'str' object does not support item assignment



In [21]:

    
word = 'bob'
word = 'B' + word[1:]
print word

Bob

Searching inside strings



In [22]:

    
def find(word, letter):
    index = 0
    while index < len(word):
        if word[index] == letter:
            return index
        index = index + 1
    return -1

print find( "puppy dog", "y" )



In [25]:

    
phrase = "puppy dog"
space = find( phrase, " " )
print phrase[:space]
print phrase[space+1:]









    



puppy
dog



In [30]:

    
def find(word, letter, index):
    while index < len(word):
        if word[index] == letter:
            return index
        index = index + 1
    return -1

print find( "puppy dog", "y", 5 )

-1

String methods



In [31]:

    
word = "banana"
print word.upper()









    



BANANA



In [32]:

    
print word.find('a')



In [33]:

    
print "dog".upper()

DOG



In [ ]: