cs 14.1-4
Which 2 operators can be used for mathematical addition and string concatenation?
+ and +=
Like arrays, the first index of a string is ___________
0 and the last index is the length minus 1
If a string has a length of 26 characters, what is its last index?
25
What is a string literal?
A set of characters delimited with quotations
What is a string?
A set of characters that behaves as a single unit
Write a statement that supports the argument that "a string is a simple data type."
A variable stores one string value; therefore, it is an example of a simple data type
Write a statement that supports the argument that "a string is a data structure."
A variable stores several character values; therefore, it is an example of a data structure
Refer to the previous question. What would be the output of this program segment? fruit = "ORANGE" print(fruit[2:5]) print(fruit[1:]) print(fruit[:2])
ANG RANGE OR
Look at program StringOperators07.py and its outputs. Explain why the 4th output says "apple goes alphabetically after ZEBRA".
Capital letters have smaller code values; String values cannot be compared properly when one starts with a lowercase letter and the other with a capital.
What is the output of print("Apples" == "Oranges") ?
False
When working with strings, what is the difference between functions find and rfind?
Find starts at the beginning of the string and searches forwards, while rfind stars at the end of the string and searches backwards
Look at program StringCommands10.py and its output and refer back to question #15. Explain how this program fixes the issue from program StringOperators07.py.
It uses the upper command to convert apple to APPLE to have it properly compared
Refer to your answer to the previous question. For quite some time, we have used this same operator for ___________________________.
Multiline comments
Suppose you have a really, really long string literal. List 2 ways make the entire string literal visible on the computer screen.
Multiple sections of the string on separate lines with + & \, multiple sections of the string can be combined with parentheses
In the previous chapter, you learned that the reverse function will "reverse" the order of items in an array. Does reverse work with strings?
No
When isolating a substring, do you get an error if either of the numbers is too large?
No, the substring will just go to the end of the string
Look at program StringCommands06.py, specifically at lines 10 and 11. Do these lines of code alter the value of the original string s1?
No, they return an altered copy of the original
Assume string q has a length of 10. What would be the output of print(q[11]) ?
Run-time error with index out of range message
isprintable
The entire string contains any of the characters that you can type. Also could be an empty string.
istitle
The first letter of every word in the string is capitalized. The rest are lowercase.
What is concatenation?
The joining together of two or more strings
Refer to your answer to the previous question. Why are these called overloaded operators?
They can perform more than one job (as in mathematical addition and string concatenation)
What happens if you try to convert "2.71828" to an integer or "Hello World" to a real number?
This would be a run-time error
What operator is used to define a multiline string literal?
Triple-double quote (""")
What is the output of print("Apples" == "Apples")
True
The characters in a string include 4 things. List them.
Upper-case letters, lower-case letters, numerical digits, and large sets of symbols for a variety of purposes
Give a couple examples of something that involves String Processing.
Word processing term papers, sending emails, and responding to online surveys
Can a multiline string literal be stored in a variable?
Yes
Look at program StringCommands07.py, specifically at lines 7 and 10. Do these lines of code alter the value of the original string s1?
Yes because they make s1 = the altered version of itself
In the previous chapter, you learned that the len function returns the number of items in an array. Does len work with strings? If so, what does it return?
Yes, len returns the number of characters in a string
Explain how to display a string in reverse order.
You count from the last index (n-1) to the first index (0) backwards (n-1,-1,-1) s = "computer", n = len(s), and r = "" for k in range(n-1,-1,-1): r += s[k] print(r) retupmoc
isupper
all letters in the string are UPPERCASE
islower
all letters in the string are lowercase
split command
breaks a sentence into words
Consider this statement: city = "Dallas" What is the string variable and what is the string literal?
city is the string variable and "Dallas" is the string literal
isdecimal
entire string contains 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
isdigit
entire string contains 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, ¹, ², ³
isnumeric
entire string contains 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, ¹, ², ³, ¼, ½, ¾
isspace
entire string contains invisible characters like space, tab or new line
isalpha
entire string contains letters
isalnum
entire string contains letters or 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
isidentifier
entire string contains letters or 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 or _ and starts with a letter
What command will convert strings to real numbers?
float
Suppose, for whatever reason, you wanted a string that contains the word "Hello" 100 times. Write the code that will generate this string, called greeting, using the word "Hello" only once.
greeting = "Hello" * 100
What command will convert strings to integers?
int
In Python, arrays and strings can only be multiplied by __________ values.
integer
If your string has a mixture of CAPITAL letters, lowercase letters, digits, and symbols, the upper function will only affect the _____________ ____________ in the string. Likewise, the lower function will only affect the ______________ ____________ in the string.
lowercase letters; uppercase letters
Consider this statement: fruit = "ORANGE" Write the code necessary to display the 'G'.
print(fruit[4])
What command will convert integers, real numbers and Boolean values to strings?
str
Refer to the previous question. Would it have worked if the lower function was used instead?
yes
Can strings be traversed, like arrays?
yes with the for loop