Outline for January 13, 2012

1. Python, files and shells
1. Python: programming language that you use to tell the computer what to do
2. Shell: what you can type Python statements directly into, to see what they do
3. IDLE: the program that interprets Python statements (executes the Python program)
4. File: type Python statements into this, and then have IDLE execute those statements by running the program in the file
2. Example: program to convert temperature \program{tempcvt.py}
1. Do we go from Fahrenheit to Celsius, Celsius to Fahrenheit, or both?
1. Go from Celsius to Fahrenheit
2. Steps in the program:
1. Ask user for temperature in Celsius
2. Convert to Fahrenheit (F = (9/5)C + 32)
3. Print result in Fahrenheit
3. Implementation (line by line)
3. Type converter functions int, float, str
4. Expressions
1. Operators +, -, *, /, //, %, **
2. Precedence
1. Parentheses for grouping ((, ))
2. Exponentiation (**); associates right to left
3. Positive, negative (unary +, -)
4. Multiplication, division, integer division, remainder (*+, /, //, %)
5. Addition, subtraction (binary +, -)
6. In general, operators of equal precedence are evaluated from the left to the right (associativity); exception noted above
5. Simple assignment: variable = expression
6. Input: input statement
1. input(prompt) prints prompt, waits for user
2. When user hits enter, it returns what was typed as a string

ECS 10, Basic Concepts of Computing Winter Quarter 2012