CSE 1310 - Assignments - Programming Assignment 4

The assignments will be graded out of 100 points. Create a text document entitled answers.xxx (where you replace xxx with whatever extension is appropriate, depending on the file format you use). Acceptable file formats are plain text, Word document, OpenOffice document, and PDF. Put your name and UTA ID at the top. Your answers that are not part of a program will be added to this file. Each task below will instruct you where to put your answers.

Task 1 (10 pts.)

The following code is supposed to ask the user for a string S and print the length of S as well as the first and last characters. It contains multiple errors. In your answers.xxx file, explain exactly what the errors are. Do not simply repeat any Python error message or just give a correction. Note that an error may be a conceptual error, not an error that causes the program to crash. Then, write a corrected version of the program and save as task1.py.

S = input('Enter a string: ')
length = len(S)
first_character = S[1]
last_character = S[length]
print('Length:', length)
print('First:', first_character)
print('Last:', last_character)

Task 2 (10 pts.)

The following code is supposed to:

• Create a string called s.
• Convert string s to a list called l.
• Print each item of list l on a separate line.

s = 'This isn't a number'
l = list(s)
for char in l:
    print(l[char])

Task 3 (10 pts.)

Write a program that:

• Asks the user to enter a string text.
• It prints out text, with all occurrences of letters p, q, r, s, t (both lower-case and upper-case) removed.

For example:

• For input 'hello world' it should print hello wold.
• For input 'Today it is Tuesday' it should print oday i i ueday.

Save the code in file task3.py.

Task 4 (30 pts.)

Write a program that:

• Asks the user to enter a string text.
• It prints out, for every letter in text, how many times it occurs in text.
• In the printout, letters should appear in the order in which they appear in the text, but no letter should appear twice.
• For any letter, you should show the TOTAL number of times it shows up in either upper case or lower case (do not count or display upper and lower cases separately).
• Spaces and punctuation characters should also be counted.

For example:

• For input 'hello world!' it should print:

  h: 1
  e: 1
  l: 3
  o: 2
   : 1
  w: 1
  r: 1
  d: 1
  !: 1
  

• For input 'Today it is Tuesday' it should print:

  t: 3
  o: 1
  d: 2
  a: 2
  y: 2
   : 3
  i: 2
  s: 2
  u: 1
  e: 1
  

Save the code in file task4.py.

Task 5 (10 pts.)

• It asks the user to enter a string text.
• It prints True if each character in text is either white space (you can use the isspace method of strings for that), a dot (character "."), a minus sign (character "-"), or a digit (0, 1, 2, 3, 4, 5, 6, 7, 8, 9).
• It prints False otherwise, i.e., if any character in text is neither white space, nor a dot, nor a digit.

• For input "32.14" it should print True.
• For input " 32 .14 " it should print True.
• For input "number 32.14" it should print False, since it contains letters.
• For input " 32!#.14 " it should print False, since it contains punctuation.

Save your code in file task5.py.

Task 6 (10 pts.)

• It asks the user to enter a string text.
• It prints True if the string has zero or one dot characters ("." characters).
• It prints False otherwise, i.e., if text contains two or more dots.

For example:

• For input "32.14" it should print True.
• For input " 32 14 " it should print True.
• For input "number 32.14" it should print True.
• For input " a.32!#.14 " it should print False, since it contains two dots.

Task 7 (10 pts.)

• It asks the user to enter a string text.
• It prints True if the string has no white space characters between non-white-space characters.
• It prints False otherwise, i.e., if text contains one or more white-space characters between non-white-space characters (again, you can use the string method isspace to check if a character is white space).

For example:

• For input "32.14" it should print True.
• For input " 32.14 " it should print True, since all white space characters are at the beginning or the end.
• For input " a.32!#.14 " it should print True, since all white space characters are at the beginning or the end.
• For input " 32 14 " it should print False, since there is white space between "32" and "14".
• For input "number 32.14" it should print False, since there is white space between "number" and "32.14"
• For input " nu mber 3 2.1 4 " it should print False, since there are several cases where white space appears between non-white-space characters.

Task 8 (10 pts.)

• It asks the user to enter a string text.
• It prints True if the string contains a valid float number, and can be safely be cast to a float using the float function.
• It prints False otherwise, i.e., if the string does not contains a valid float number, and float(text) produces an error message.

For example:

• For input "32.14" it should print True.
• For input " 32.14 " it should print True.
• For input " a.32!#.14 " it should print False, since float(" a.32!#.14 ") gives an error message.
• For input " 32 14 " it should print False, since float(" 32 14 ") gives an error message.
• For input "number 32.14" it should print False, since float("number 32.14") gives an error message.
• For input " 44.21.12 " it should print False, since float(" 44.21.12 ") gives an error message.

Suggestions

How to submit

The assignment should be submitted via Blackboard. Submit a ZIPPED directory called assignment4.zip (no other forms of compression accepted, contact the instructor or TA if you do not know how to produce .zip files). The zipped directory should contain your answers.xxx document and all the Python code files (task5.py, task6.py, etc).

Submission checklist

• Did you create the answers.xxx file with your name, UTA ID, and answers to non-programming tasks?
• Did you zip everything into a file called assignment2.zip?