Intro Flashcards
how to set up a string
( )
what is a string
anything in the ( )
what is a variable and how do we asing a variable
If there is a greeting we want to present, a date we need to reuse, or a user ID we need to remember we can create a variable which can store a value. In Python, we assign variables by using the equals sign (=).
How to set up a variable and print
e.g lunch=”toast”
print(“lunch”)
what is a syntax error
SyntaxError means there is something wrong with the way your program is written — punctuation that does not belong, a command where it is not expected, or a missing parenthesis can all trigger a SyntaxError.
What is a name error
A NameError occurs when the Python interpreter sees a word it does not recognize. Code that contains something that looks like a variable but was never defined will throw a NameError.
what is a int
Whole number
what is a float
decimal number you cana define an int and float as variables
what is a literal number
We call the number 3 here a literal, meaning it’s actually the number 3 and not a variable with the number 3 assigned to it.
how to set a varible using number
e.g rating = 4.5.
(dosn’t need strings)
what are the maths symbols you can use in python
multiplication, and division with +, -, *, and /.
e.g
Prints “500”
print(573 - 74 + 1)
Prints “50”
print(25 * 2)
Prints “2.0”
print(10 / 5)
how can Two variables can be added together that are assigned numbers
coffee_price = 1.50
number_of_coffees = 4
Prints “6.0”
print(coffee_price * number_of_coffees)
# Prints “1.5”
print(coffee_price)
# Prints “4”
print(number_of_coffees)
Performing arithmetic on variables does not change the variable — you can only update a variable using the = sign.
What is a exponent
the power of
what is a modulo operator
The modulo operator is indicated by % and gives the remainder of a division calculation. If the two numbers are divisible, then the result of the modulo operation will be 0.
Prints 4 because 29 / 5 is 5 with a remainder of 4
print(29 % 5)
example of modulo
print(3 % 3) # Prints 0
print(4 % 3) # Prints 1
print(5 % 3) # Prints 2
print(6 % 3) # Prints 0
print(7 % 3) # Prints 1
acts as a clock it will always reset
In each of these modulo operations, 3 is the divisor. Since 3 / 3 equals 1 with no remainder, the result of the first modulo operation is 0. Note that as the dividend increases by 1, the remainder also increases by 1, until we reach the next number that is evenly divisible by 3 — this creates a pattern that repeats contiuously as the dividend increases by 1!
when is a modulo useful in programming
Because of this, the modulo operator is useful in programming when we want to perform an action every nth time something occurs. Imagine you own a small café and would like for every 7th customer to receive a survey. If every customer transaction is numbered in the order they occur, you can determine which customers should receive the survey by calculating <transaction> % 7 — if the result is 0, hand out the survey!</transaction>
what does the % does in the modulo
The modulo operator is indicated by % and gives the remainder of a division calculation.
what is Concatenation
The + operator doesn’t just add two numbers, it can also “add” two strings! The process of combining two strings is called string concatenation. Performing string concatenation creates a brand new string comprised of the first string’s contents followed by the second string’s contents (without any added space in-between).
what is an example of concatrnation
greeting_text = “Hey there!”
question_text = “How are you doing?”
full_text = greeting_text + “” + question_text
Prints “Hey there!How are you doing?”
print(full_text)
how to you add a number to a concatenateion
using the str( ) function.
e.g birthday_string = “I am “
age = 10
birthday_string_2 = “ years old today!”
full_birthday_string = birthday_string + str(age) + birthday_string_2
Prints “I am 10 years old today!”
print(full_birthday_string)
what is plus equals
a shorthand for updating variables. When you have a number saved in a variable and want to add to the current value of the variable, you can use the += (plus-equals) operator.
what is can example of plus equals
number_of_miles_hiked = 12
Then we need to update that variable
# Let’s say we hike another two miles today
number_of_miles_hiked += 2
The new value is the old value
# Plus the number after the plus-equals
print(number_of_miles_hiked)
# Prints 14
show example of +=
We’re doing a little bit of online shopping and find a pair of new sneakers. Right before we check out, we spot a nice sweater and some fun books we also want to purchase!
Use the += operator to update the total_price to include the prices of nice_sweater and fun_books.
what is a multi line string
Python strings are very flexible, but if we try to create a string that occupies multiple lines we find ourselves face-to-face with a SyntaxError.
example of +=
number_of_miles_hiked = 12
number_of_miles_hiked += 2
print(number_of_miles_hiked)
# Prints 14
how to set a multi line string
Python offers a solution: multi-line strings. By using three quote-marks (“”” or ‘’’) instead of one, we tell the program that the string doesn’t end until the next triple-quote.
what is input ( )
The input() function requires a prompt message, which it will print out for the user before they enter the new information. For example:
likes_snakes = input(“Do you like snakes? “)
