week 1- intro to python Flashcards
incremental development
writing, compiling, and testing code in small amounts
program specifications
output statements and submit for grading after each step
program
instructions executing one at a time
input -> process -> output
input
program gets data from file, keyboard, touchscreen, etc
process
program preforms computations on that data
output
program puts data somewhere
variables
used to refer to data, like x
computational thinking
creating sequence of instructions to solve a problem
algorithm
sequence of instructions that solves a problem
python interpreter
computer program that executed code written in python coding language
code
textual representation of a program
line
row of code
interactive interpreter
program that allows code to execute one line at a time
prompt («<)
indicates interpreter is ready to accept code
statement
program instruction, on its own line
expression
code that returns value when evaluated (ex: x*y)
assignment
= sign, used to create new variable
print()
displays variables or expression values
comments #
notes written by programmer
string literals
letters, numbers, spaces, and symbols in quotes “ “
newline
ourput after every print(), each use of print() should start on a new line
keeping output on same line
add end = ‘ ‘ inside of print function for lines to be separated by single space
commas
used to separate different items in output
newline character /n
output can move to next line
whitespace
any space, tab, or newline
input()
allows user to input values, causes interpreter to wait for input before continuing
string
sequence of character
‘Hello’ is ‘H’ ‘e’ ‘l’ ‘l’ ‘o’
type
determines how a value can behave (ex: string, integers)
int()
can convert string to integer
input prompt
add string into input function to give user prompt before they input data
syntax error
violates programming rules on how symbols can be combined
ex: putting multiple print() on one line
runtime error
program attempts impossible operation, like divide by 0
crash
abrupt and unintended termination of a program
indentation error
lines of a program aren’t properly indented
value error
invalid values used
ex: letters in int()
name error
program tries to use variable that doesn’t exist
type error
operation uses incorrect types
ex: adding integer to a string
logic error
program loads correctly but doesn’t behave as expected (aka bug)
switch
controls whether or not electricity flows
1
positive, electricity flows
0
zero, prevents flow of electricity
bits
0s and 1s that build connections
processors
circuits created to execute list of desired calculations
instruction
list of desired calculations
memory
circuit that can store 1s and 0s
machine instructions
instructions in bits (1s and 0s)
executable program
sequence of machine instructions together
assembly language instructions
machine learning instructions translated to human readable form
assemblers
translate machine learning instructions to assemble language instructions
high-level languages
support programming w/ formulas or algorithms
compilers
programs that translate high level languages into executable program
input/output devices
screens display output and keyboards allow user to input data
storage
disk/hard drive stores files and other data
memory
RAM (random access memory) temporarily holds and reads data from storage, RAM us more costly per bit but runs faster
bytes
8 bit segments
proessor
runs computer program by reading and executing instructions from memory (aka CPUs)
operating system
allows user to run other programs and interfaces with many peripherals
cache
memory accessible in one clock tick, processor chip with small amount of RAM
clock
in processor, ticks at specific frequency to govern rate of processor’s executions
integrated circuit (IC)
smaller switches, also known as transistors
moore’s law
doubling of IC capacity every 18 months
scripting languages
executes program without need for compilation
script
program whose instructions are executed by interpreter
advantages of script
avoids compilation step, you can run the same script on different processors
backward compatible
older versions run on newer ones, python is NOT backward compatible
python
scripted language created by Van Rossum in late 1980s
disadvantage of scripts
slower and requires multiple interpreter instructions
open source
user community participates in defining a language and creating new interpreters
precision
small details like correct spelling, case, and whitespace
