Outline for October 13, 2025

Reading: §4.5, 4.9, 6, 8
Assignments: Homework 1, due October 15, 2025

1. String methods: methods that change, add, or delete characters do not alter the string to which they are applied; they return a new string that is a copy of the old string, suitably modified

2. String methods: type of characters in string (return True or False) [strtype.py]
   1. S.isalpha() — True if only alphabetics (letters) in S
   2. S.isalnum() — True if only alphanumerics (letters or digits) in S
   3. S.isdigit() — True if only digits in S
   4. S.isspace() — True if only white space (blanks, tabs, newlines) in S
   5. S.isupper() — True if all letters in S are upper case
   6. S.islower() — True if all letters in S are lower case

3. String methods: changing case of letters in string (return result of applying method) [strchcase.py]
   1. S.capitalize() — If the first character of S is a letter, capitalize it
   2. S.title() — Capitalize each word in S
   3. S.lower() — Change all upper case letters in S to lower case
   4. S.upper() — Change all lower case letters in S to upper case
   5. S.swapcase() — Change all upper case letters in S to lower case and vice versa

4. String methods: stripping blanks from strings (return result of applying method) [strstrip.py]
   1. S.lstrip() — Delete all leading white spaces from S
   2. S.rstrip() — Delete all trailing white spaces from S
   3. S.strip() — Delete all leading and trailing white spaces from S

5. String methods: find characters and substrings (return position or cause exception) [strfind.py]
   1. S.find(s) — Return the index of the first occurrence of s in S; −1 if s not in S
   2. S.index(s) — Return the index of the first occurrence of s in S; ValueError exception if s not in S
   3. S.rfind(s) — Return the index of the last occurrence of s in S; − if s not in S
   4. S.rindex(\sstr) — Return the index of the last occurrence of s in S; ValueError exception if s not in S

6. String methods: miscellaneous [strmisc.py]
   1. S.count(s) — Return the number of times s occurs in S
   2. S.startswith(s) — True if S starts with s
   3. S.endswith(s) — True if S ends with s
   4. S.replace(s,t) — Replace all occurrences of s with t in S

7. What you can do with lists
   1. Check membership: in, not in
   2. +: concatenation
   3. *: repetition
   4. list[a:b]: slice list from a to b−1
   5. del list[i]: delete element list[i]; i can be a slice

8. Objects, references, aliasing
   1. For strings, one copy: assume a = "banana"
      1. After b = a or b = a[:], then a is b is True
   2. For lists, multiple copies: assume A = [ 1, 2, 3 ]
      1. After B = A then A is B is True
      2. After B = A[:], then A is B is False

9. Lists and strings [datecvt.py]

10. Program to print words in a line [lines.py]

11. What you can do with lists
    1. Add elements to, remove elements: L.append(x), L.extend(ls), L.insert(i, x), L.pop(), L.remove(x)
    2. Element ordering: L.reverse(), L.sort()
    3. Other: L.count(x), L.index(x)

12. Searching a list
    1. Example use: linear search [linsearch.py]

13. isinstance(obj,type) function
    1. type is bool, float, int, list, str, tuple

14. Lists as parameters: can change list elements in function and they are changed in caller [args2.py]

15. More on parameters: named arguments and variable number of arguments [args3.py]

16. Recursion
    1. n factorial [nfact.py]

17. Thinking recursively [recfun.py]
    1. First: think of the recursive case (write the problem in terms of something involving a smaller instance of the problem)
    2. Next: think of base case (when to stop)
    3. Example: Find the length of a string
    4. Example: Does the string only have alphabetic characters in it?
    5. Example: Find the maximum element of a list
    6. Example: Construct a string from a list of strings
    7. Example: Reverse a string

18. Recursion
    1. Palindromes [palindrome.py]
    2. Fibonacci numbers [rfib.py]
    3. Sum of digits [sumdigits.py]
    4. Nested lists: is an item in a list? [isinlist.py]

Matt Bishop Office: 2209 Watershed Sciences Phone: +1 (530) 752-8060 Email: mabishop@ucdavis.edu

MHI 289I, Programming in Health Informatics Version of October 15, 2025 at 6:47AM

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