Python For Informatics Chapter 1

Front 1

The Central Processing Unit

Back 1

(or CPU) is that part of the computer that is
built to be obsessed with “what is next?”. If your computer is rated at 3.0 Gigahertz, it means that the CPU will ask “What next?” three billion times
per second.

Front 2

The Main Memory

Back 2

is used to store information that the CPU needs in a hurry. The main memory is nearly as fast as the CPU. But the information stored in the main memory vanishes when the computer is turned off.

Front 3

The Secondary Memory

Back 3

is also used to store information, but it is much
slower than the main memory. The advantage of the secondary memory is that it can store information even when there is no power to the computer. Examples of secondary memory are disk drives or flash memory (typically found in USB sticks and portable music players).

Front 4

The Input and Output Devices

Back 4

are simply our screen, keyboard, mouse,
microphone, speaker, touchpad, etc. They are all of the ways we interact with the computer.

Front 5

program

Back 5

stored instructions

Front 6

programming

Back 6

The act of writing these instructions down and getting the instructions to be correct.

Front 7

programmer

What do you need?

Back 7

A person skilled in the art of programming.

-You need to know the programming language (Python) - you need to know the vocabulary and grammar, spell, construct "sentences."

-You need to "tell a story." Convey an idea to the reader. In programming, our program is the "story" and the problem you are trying to solve is the "idea."

Front 8

"vocabulary"

Back 8

The "reserved words"

These are words that have very special meaning to Python. When Python sees these words in a Python program, they have one and only one meaning to Python.

These words can not be used for anything else within Python.

Front 9

variables

Back 9

Words you write that you make your own word with it's own meaning.

x = 5

x is the variable and 5 and is the meaning you made the variable have.

Front 10

script

Back 10

The use of a text editor to write the Python instructions into a file. The file name must end with .py

Front 11

program

Back 11

A sequence of Python statements that have been crafted to do something.

Front 12

input

Back 12

Get data from the the “outside world”. This might be reading data froma file, or even some kind of sensor like a microphone or GPS. In our initial
programs, our input will come from the user typing data on the keyboard.

Front 13

output

Back 13

Display the results of the program on a screen or store them in a file or perhaps write them to a device like a speaker to play music or speak text.

Front 14

sequential execution

Back 14

Perform statements one after another in the order they are encountered in the script.

Front 15

conditional execution

Back 15

Check for certain conditions and execute or skip a sequence of statements.

Front 16

repeated execution

Back 16

Perform some set of statements repeatedly, usually with some variation.

Front 17

reuse

Back 17

Write a set of instructions once and give them a name and then reuse those instructions as needed throughout your program.

Front 18

Syntax errors

Back 18

A syntax error means that you have violated the “grammar” rules of Python.

note : Python does its best to point right at the line and character where it noticed it
was confused. The only tricky bit of syntax errors is that sometimes the mistake
that needs fixing is actually earlier in the program than where Python noticed it was confused. So the line and character that Python indicates in a
syntax error may just be a starting point for your investigation.

Front 19

Logic Errors

Back 19

A logic error is when your program has good syntax but there is
a mistake in the order of the statements or perhaps a mistake in how the
statements relate to one another. A good example of a logic error might be,
“take a drink from your water bottle, put it in your backpack, walk to the
library, and then put the top back on the bottle.”