Outline for October 22, 2020

Reading: §6
Due: Homework 2, due October 30, 2020

  1. I modified homework 2, question 2, so the function isabcde(s) need not be recursive.

  2. Sequences
    1. Sequences are a series of values in a particular order
    2. In Python predominantly strings and lists but also sets and tuples

  3. Strings
    1. Sequence of characters (characters are strings of length 1)
    2. Strings are immutable; really important for functions

  4. Basic string operations
    1. +, concatenation for strings
    2. *, repetition repeats given value
    3. len() returns length of sequence
    4. s in str returns True if s is a substring of str, False otherwise

  5. Indexing, var[position]
    1. Count from 0 to len(var)−1
    2. Position can be a negative number to count from right

  6. Assignment with indexing doesn’t work as strings immutable;
    x = ’hEllo’; x[1] = ’e’ produces an error

  7. Slicing, var[start:end]
    1. Value at index end not included in slice
    2. If omitted, starting value defaults to 0 and ending value defaults to last index + 1
    3. Can use negative index

  8. Looping over strings: for i in str

  9. Example program [strstuff.py]

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Matt Bishop
Office: 2209 Watershed Sciences
Phone: +1 (530) 752-8060
Email: mabishop@ucdavis.edu
MHI 289I, Programming for Health Informatics
Version of October 21, 2020 at 11:15AM

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