Intro-To-Python

This content is based on the book Think Python 2nd Edition by Allen B. Downey. More information about the book can be found here.

Lecture/discussion notes organized by chapter. Links for each of these are below.

Ch.2: Variables, expressions, and statements

Ch.3: Functions

Ch.4: Interface design

Ch.5: Conditionals and Recursion

Ch.6: Fruitful functions

Ch.7: Iteration

Ch.8: Strings

Ch.9: Word play

Ch.10: Lists

Ch. 11: Dictionaries

Ch. 12: Tuples

Math

math

Variable and Methods

Assignment statements

An assignment statement creates a new variable and gives it a value:

#!/bin/python3
quote = "All is fair in love and war"
print(quote)

Python 3 has these keywords:

Keywords
False, class, finally, is, return
None, continue, for, lambda, try
True, def, from, nonlocal, while
and, del, global, not, with
as, elif, if, or, yield
assert, else, import, pass
break, except, in, raise

Adding a method

#!/bin/python3
quote = "All is fair in love and war"
print(quote`.upper()`)

The method upper() is assigend to the object.

Glossary

variable: A name that refers to a value.

assignment: A statement that assigns a value to a variable.

state diagram: A graphical representation of a set of variables and the values they refer to.

keyword: A reserved word that is used to parse a program; you cannot use keywords like if, def, and while as variable names.

operand: One of the values on which an operator operates.

expression: A combination of variables, operators, and values that represents a single re-sult.

evaluate: To simplify an expression by performing the operations in order to yield a single value.

statement: A section of code that represents a command or action. So far, the statements we have seen are assignments and print statements.

execute: To run a statement and do what it says.

interactive mode: A way of using the Python interpreter by typing code at the prompt. script mode: A way of using the Python interpreter to read code from a script and run it.

script: A program stored in a file. order of operations: Rules governing the order in which expressions involving multiple operators and operands are evaluated.

concatenate: To join two operands end-to-end.

comment: Information in a program that is meant for other programmers (or anyone read- ing the source code) and has no effect on the execution of the program.

syntax error: An error in a program that makes it impossible to parse (and therefore im- possible to interpret).

exception: An error that is detected while the program is running.

semantics: The meaning of a program.

semantic error: An error in a program that makes it do something other than what the programmer intended