Ch. 5 Flashcards
strings, lists, files
accessing a single character out of a string is called
indexing
which of the following is same as [0:-1]
s[:len(s)-1 ]
what function gives the unicode value of a character?
ord
which of the following can not be used to convert a string of digits into a number
eval
a successor to ASCII that includes characters from (nearly) all written languages is
unicode
Which string method converts all the characters of a string to upper case?
upper
The string “slots” that are filled in by the format method are marked by:
{}
which of the following is not a file-reading method in python
readall
the term for a program that does its input and output with files is
batch
Before reading or writing to a file, a file object must be created via:
open
s1 = “spam”
s2 = “ni!”
“The Knights who say, “ + s2
the knights who say ni!
s1 = “spam”
s2 = “ni!”
3 * s1 + 2 * s2
spamspamspamni!ni!
s1 = “spam”
s2 = “ni!”
s1[1]
p
s1 = “spam”
s2 = “ni!”
s1[1:3]
pa
s1 = “spam”
s2 = “ni!”
s1[2] + s2[:2]
ani
s1 = “spam”
s2 = “ni!”
s1 + s2[-1]
spam!
s1 = “spam”
s2 = “ni!”
s1.upper()
SPAM
s1 = “spam”
s2 = “ni!”
s2.upper().ljust(4) * 3
NI! NI! NI!
s1 = “spam”
s2 = “ni!”
spam
s1
s1 = “spam”
s2 = “ni!”
NI!
s2[0:2].upper()
s1 = “spam”
s2 = “ni!”
ni!spamni!
s2 + s1 + s2
s1 = “spam”
s2 = “ni!”
spm
s1[0:2] + s1[-1]
“Looks like (1) and (0) for breakfast”.format(“eggs”, “spam”)
not legal bc curly braces are required around 1 and 0
“There is {0} {1} {2} {3}”.format(1, “spam”, 4 “you”)
‘There is 1 spam 4 you.’
“Hello {0}”.format(“Susan”, “Computewell”)
‘Hello Susan’
“{0:0.2f} {0:0.2f}”.format(2.3, 2.3468)
‘2.30 2.30’
“{7.5f} {7.5f}”.format(2.3, 2.3468)
not legal bc no index followed
“Time left {0:02}:{1:05.2f}”.format(1, 37.374)
‘Time left 1:37.37’
“{1:3}”.format(“14”)
‘14’
Explain why public key encryption is more useful for securing communications on the Internet then private (shared) key encryption.
private keys use the same key for locking and unlocking, while public keys use one to lock and a different key to unlock
a certain CS professor gives 5 point quizzes that are graded on the scale 5-A, 4-B, 3-C, 2-D, 1-F, 0-F. Write a program that accepts a quiz score as an input and prints out the corresponding grade
lettergradescale = “FFDCBA”
quizgrade = int(input(“Please enter the quiz grade on a scale from 0 to 5: “))
lettergrade = lettergradescale[quizgrade]
print(“Your quiz grade of {0} corrsesponds to the letter grade of {1}.”.format(quizgrade, lettergrade))
write a program that allows the user to type in a phrase and then outputs the acronym for that phrase. Note: the acronym should be all uppercase, even if the words in the phrase are not capitalized
def get_acronym(phrase):
words = phrase.split()
acronym = ‘‘.join(word[0].upper() for word in words)
return acronym
input_phrase = input(“Enter a phrase to generate an acronym: “)
acronym = get_acronym(input_phrase)
print(“The acronym for ‘{0}’ is ‘{1}’.”.format(input_phrase, acronym))
write a program that calculates the numeric value of a single name provided as input
def calculate_numeric_value(name):
name = name.upper()
numeric_value = 0
for letter in name:
if letter.isalpha():
numeric_value += ord(letter) - ord('A') + 1
return numeric_value
input_name = input(“Enter a name to calculate its numeric value: “)
result = calculate_numeric_value(input_name)
print(“The numeric value of ‘{0}’ is {1}.”.format(input_name, result))
