Strings_Reading_4.1

Question

1. Assume that the variable data refers to the string “myprogram.exe”

     Write the values of the following expressions:

1. data[2]
2. data[-1]
3. len(data)
4. data[0:8]
5. “gram” in data and “pro” in data
6. Assume that the variable data refers to the string “myprogram.exe”.

     Write the expressions that perform the following tasks:

1. Extract the substring “gram” from data.
2. Truncate the extension “.exe” from data.
3. Extract the character at the middle position from data.
4. Assume that the variable myString refers to a string. Write a code segment that uses a loop to print the characters of the string in reverse order.
5. Assume that the variable myString refers to a string and the variable

      reversedString refers to an empty string. Write a loop that adds the characters from myString to reversedString in reverse order.

Answer 1

######################################

def reverseStr(Str):

revStr = " "

nLength = len(Str)

for i in range(nLength-1,-1,-1):

chChar = Str[i]

revStr = revStr + chChar

return revStr.strip()

###########################################

def printStrBackwards( str):

print(reverseStr(str))

########################################

data = "myprogram.exe"

print(data[2]) #the output is the character 'p', the 3rd character

print(data[-1]) #the output is the character 'e' the last character

nLength = len(data)

print(len(data)) #length of the string is 13

print(data[0:8]) # the output is "myprogra"

# starts at index zero, then the next 8 characters

print(data[2:5]) # starts at index 2, then the next 3 characters

print(data[5:9]) #starts at index 5, then the next 4 characters

print(data[10:13])

print("middle char is " + data[nLength//2])

printStrBackwards(data)