11-9-1: What is printed by the following statements?
s = "python rocks"
print(s[1] * s.index("n"))
yyyyy
Correct! s[1] = y and the index of n is 5, so y * 5 prints 5 y characters.
55555
Incorrect! s.index("n") = 5, but it is multiplying something else. Try again.
y5
Incorrect! The print statement contains multiplication. Try again.
TypeError
Incorrect! Multiplying a string by an int is allowed. Try again.
2.
11-9-2: What will be printed when the following executes?
str = "His shirt is red"
pos = str.find("is")
print(pos)
1
Correct! The find function returns the index of the first position that contains the given string.
9
Incorrect! The find function returns the index of the FIRST position that contains the given string. Try again.
2
Incorrect! Remember, indices start at 0, not 1. Try again.
pos
Incorrect! pos is a variable, so print will print its value. Try again.
3.
11-9-3: What will be printed when the following executes?
str = "This is fun"
str = str[5]
print(str)
i
Correct! This will print the character at position 5 in the string, which is i.
' '
Incorrect! Remember, indices start at 0. Try again.
is fun
Incorrect! str[5] equals one specific character of the larger string. Try again.
This is fun
Incorrect! Line 2 permanently changes the value that the variable str is assigned to. Try again.
4.
11-9-4: What is the value of s1 after the following code executes?
s1 = "heY"
s1 = s1.capitalize()
s1.lower()
heY
Incorrect! Although strings are immutable, s1 gets reassigned to a different value than it begins with. Try again.
hey
Incorrect! Strings are immutable, so line 3 just returns a new string and doesn't modify the original. Try again.
HEY
Incorrect! The capitalize method doesn't capitalize the entire word. Try again.
Hey
Correct! The capitalize method capitalizes the first letter of the word and lowercases the rest. Then, line 3 returns a new string without modifying the original.
5.
11-9-5: What would the following code print?
Mali = 5
print("Mali" + " is " + str(Mali))
Mali is Mali
Incorrect! There are no quotes around the last Mali, so str() will use the value of the variable Mali. Try again.
Mali is 5
Correct! The first Mali is in quotes, so it will print the string "Mali". The second Mali is not in quotes, so it will print the value of the variable Mali.
5 is Mali
Incorrect! The first Mali is in quotes and the second is not. Try again.
5 is 5
Incorrect! The first Mali is in quotes, so it is a string, not a variable. Try again.
6.
11-9-6: What is printed by the following statements?
s = "python rocks"
print(s[3])
t
Incorrect! Indices start at 0, not 1. Try again.
h
Correct! Indices start with 0.
c
Incorrect! s[-3] would count from right to left and return c. Try again.
Error, you cannot use the [ ] operator with a string.
Incorrect! [ ] is the index operator and works with strings. Try again.
7.
11-9-7: What is printed by the following statements?
s = "python is awesome"
print(s[2] + s[-5])
te
Correct! The indexing operator has precedence over concatenation.
tw
Incorrect! s[-1] is the last character of the string, so what is s[-5]? Try again.
o
Incorrect! The indexing operator happens before the two strings are concatenated. Try again.
Error, you cannot use the [ ] operator with the + operator.
Incorrect! [ ] operator returns a string that can be concatenated with another string. Try again.
8.
11-9-8: What is printed by the following statements?
s = "python rocks"
print(len(s))
11
Incorrect! The space counts as a character. Try again.
12
Correct! len() returns the number of characters in the string, including spaces.
1
Incorrect! s is a variable, not a character. Try again.
Error, missing quotes around s
Incorrect! Because s is the name of a string variable, len() can be used on it. Try again.
9.
11-9-9: What is printed by the following statements:
s = "Rose"
s[1] = "i"
print(s)
Rose
Incorrect! Assignment is not allowed with strings. Try again.
Rise
Incorrect! Assignment is not allowed with strings. Try again.
s
Incorrect! Assignment is not allowed with strings. Try again.
TypeError
Correct! Strings are immutable, so you cannot change an existing string.
10.
11-9-10: What is printed by the following statements:
s = "ball"
r = ""
for item in s:
r = item.upper() + r
print(r)
Ball
Incorrect! Each item is converted to upper case before concatenation. Try again.
BALL
Incorrect! Pay close attention to the order the characters will be in. Try again.
LLAB
Correct! The order is reversed due to the order of the concatenation.
TypeError
Incorrect! String concatenation is allowed. Try again.
11.
11-9-11: What is printed by the following statements?
s = "python rocks"
print(s[7:11] * 3)
rockrockrock
Correct! s[7:11] = "rock", which is then repeated 3 times.
rock rock rock
Incorrect! s[7:11] is "rock", not " rock". Try again.
rocksrocksrocks
Incorrect! Slicing will not include the character at index 11, just the characters up to it. Try again.
TypeError, you cannot use multiplication with slicing.
Incorrect! Multiplying a string by an int is okay. Try again.
12.
11-9-12: What is printed by the following statements?
animal = "dog"
print("animal" + animal)
dogdog
It will print "animal" first.
dog dog
There is no added space.
animal dog
There is no added space.
animaldog
Correct! It will print the characters in the string followed by the value of the variable animal without any space between.
13.
11-9-13: What is printed by the following statements?
animal = "dog"
print("animal " + "animal")
animal animal
Since animal is in quotes it will print those exact letters.
animalanimal
There is a space in the first string.
animal dog
Notice that the second animal is also in quotes.
animaldog
Notice that the second animal is also in quotes and there is a space after the first string.
