Telephone numbers used to be encoded with letters so that it was easier to remem

Question

Telephone numbers used to be encoded with letters so that it was easier to remember numbers. The encoding was 2: abc 3: def 4: ghi 5: jkl 6: mno 7: pqrs 8: tuv 9: wxyz 0: A telephone number such as 1-414-846-6270 would represent "Thomas " and phone numbers that represent names are called vanity numbers. Any name with 7 letters can be represented by one vanity number and names with less letters can be represented by more by interspersing with the numbers 0 and 1 especially at the beginning and end Write a function that given a lower-case letter return the corresponding digit (as a letter, not as an integer.) Right now, we have to do this with case distinctions, but soon, we will learn to do it more efficiently using dictionaries. Write a function that takes a seven-digit phone number (a string, NOT an integer) and returns a string without 0 and 1 digits Write a function that tests (returns a True or False) whether a vanity number can represent a name Use the file "first.txt" that contains first names from the US census bureau. The first word on each line is a first name. Use this text file to implement a function that prints out all names that could have a given phone number as a vanity number For example, for "3284310", your function should return "david".

Explanation / Answer

# file must be saved as namefile.txt in the same directory as this python file.

# takes a letter and return a digit as a STRING.
# not used here but returns -1 of type integer if given anything
# else other than a lowercase english alphabet
def getDigit(l):
if(l=='a' or l=='b' or l=='c'):
return '2'
elif(l=='d' or l=='e' or l=='f'):
return '3'
elif(l=='g' or l=='h' or l=='i'):
return '4'
elif(l=='j' or l=='k' or l=='l'):
return '5'
elif(l=='m' or l=='n' or l=='o'):
return '6'
elif(l=='p' or l=='q' or l=='r' or l=='s'):
return '7'
elif(l=='t' or l=='u' or l=='v'):
return '8'
elif(l=='w' or l=='x' or l=='y' or l=='z'):
return '9'
else:
return -1;

# take a string of numbers as input and return after removing 'o' and '1' from it
def remove01(number):
newNumber=""
for n in list(number):
if (n!='0' and n!='1'):
newNumber=newNumber+n
return newNumber
# check if the given number is a vanity number for given name
def checkvanity(name,number):

# spliting the name into letters and getting digit for every letter
# thus coverting the given name into a vanity number
letters=list(name)
tempnumb1=""
for letter in letters:
tempnumb1=tempnumb1+getDigit(letter)

# removing '0' and '1' from the given number
tempnumb2=remove01(number)

# checking if the the converted name and the given number are equal or not.
if (tempnumb2==tempnumb1):
return True
return False

# getting names from file and checking every name against the given number.
# file must be saved as namefile.txt in the same directory as this python file.
def vanityfromfile(number):
validnames=[]
with open("namefile.txt") as f:
for line in f:
# print(line.strip().split(" ")[0])
name = line.strip().split(" ")[0].lower()
if (checkvanity(name,number)):
validnames.append(name)
return validnames
# calling the driver function against "3284310" should return david from the file.
foundnames=vanityfromfile('3284310')
for name in foundnames:
print(name)

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.