Outline for October 17, 2023

Reading: §6.9–6.10, 4.9
Due: Homework 2, due October 26, 2023

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; −1 if s not in S
   4. S.rindex(s) — 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. Lists and strings [datecvt.py]

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

9. 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
   6. Add elements to, remove elements: L.append(x), L.extend(ls), L.insert(i, x), L.pop(), L.remove(x)
   7. Element ordering: L.reverse(), L.sort()
   8. Other: L.count(x), L.index(x)

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

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

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

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

Matt Bishop Office: 2209 Watershed Sciences Phone: +1 (530) 752-8060 Email: [email protected]

ECS 235A, Computer and Information Security Version of October 16, 2023 at 9:47AM

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