Introduction to Python
Modulo
% (the remainder)
Python
A programming language
Access by index
Allows you to find the nth index of "text" by "text"[n-1]
variable
Allows you to store data in the program
not, and, or
Boolean operators, order of operations:
String
Can contain letters, numbers, and symbols
Interpreter
Checks for errors
IDE
Integrated DeveLopment Environment
Python was named after
Monty Python's Flying Circus
boolean comparators
Name the following: == != < <= > >=
print "%d squared is %d." % (n, squared)
Print "var squared is var" using signed integer decimal format.
print("%.2f" % total)
Print total to two decimals
Prints anything after this command to the screen
comma
Separates variables and strings in print statement
single line Comments
Starts with #
*.py
The Python file extension
%, %s
The ___ operator will replace a ___ in the string with the string variable that comes after it.
IndentationError: expected an indented block
The error message you receive when the whitespace is off
4 spaces
The proper number of spaces when indenting your Python code
'alpha' "bravo" str(3)
Three ways to create strings
Multi line comments
Triple '''
boolean are either....
True or false
"""..."""
Used for multi-line commenting in Python
#...
Used for single line commenting in Python
IDLE
What Python calls their "Integrated DeveLopment Environment"
Run (or F5)
Will execute your program so you can test it works
function
a block of organized, reusable code that is used to perform a single, related action
if / then statement
a conditional answered with boolean
parameter
a variable name for a passed in argument
quotes
are used to go around a string
from datetime import datetime now = datetime.now()
assigning the current date and time to a variable called 'now'
=
assigns a value to a variable
\\
backslash escape sequence to show actual backslash
\b
backspace
\r
carriage return
Area where you write your code
code editor
.lower()
converts string to lowercase
.upper()
converts string to uppercase
from datetime import datetime
datetime library
def
defining a function
len()
determines the length
\"
double quote with the backslash escape sequence
eggs = 10 ** 2
eggs = 100
==
equal to
/
evaluate as a float (with decimal)
(10 + 17) == 3**16
evaluates to be FALSE
(20 - 10) > 15
evaluates to be FALSE
-22 >= -18
evaluates to be FALSE
1**2 <= -1
evaluates to be FALSE
4**2 != 16
evaluates to be FALSE
99 != (98 + 1)
evaluates to be FALSE
True and false is ____.
evaluates to be FALSE
100 == (2 * 50)
evaluates to be TRUE
19 <= 19
evaluates to be TRUE
20 != 10*2
evaluates to be TRUE
3**2 <= 9
evaluates to be TRUE
40 * 4 >= -4
evaluates to be TRUE
5*12 >= 6
evaluates to be TRUE
True or False is ____.
evaluates to be TRUE
shortened code: value+=2
expanded code: value = value+2
print "I have " +str(2) + " coconuts!"
explicit string conversion
**
exponents
Control flow
gives us this ability to choose among outcomes based off what else is happening in the program.
>
greater than
>=
greater than or equal to
\
initiate escape sequence
name = input("What is your name?")
input syntax
<
less than
<=
less than or equal to
string
letters or characters that are printed in the program
-
minus
*
multiply
Set the variable my_bool to the value True
my_bool = True
Set the variable my_float to the value 1.23
my_float = 1.23
Set the variable my_variable equal to the value 10
my_variable = 10
\n
new line
!=
not equal to
Data types
numbers and booleans
code segment: ss = "Sammy Shark!" print(ss[4])
output: y
+
plus
from datetime import datetime now = datetime.now() print '%s:%s' %(now.hour, now.minute)
print the time
or
returns TRUE when at least one expression on either side is TRUE
and
returns TRUE when expressions on both sides are TRUE
abs()
returns the absolute value
max()
returns the largest argument
modulo
returns the remainder from a division
min()
returns the smallest argument
interpreter
runs your code line by line, and checks for any errors
\'
single quote with the backslash escape sequence
%s
string placeholder
'%s' % (str)
string substitution
\t
tab
len(), upper(), lower()
three other string methods
str()
turn non-strings into strings
from * import *
universal function import
whitespace
used in Python to structure the code
integer
used in calculations - a whole number - does NOT have quotes around them
year, day, month, time
what does datetime.now() print?
reassigning
when you change the value of a variable
4 // 5
will evaluate as an int
