Cheatography

# Python Cheat Sheet by rdw170000

Cheat sheet for the cereal data python lesson

### Concepts

 Data Type the type of the value Variable stores a value Identifier name of a variable

### Data Types

 String Sequence of characters “Hello World” Integer Whole numbers 101 Float Decimal numbers 71.24 Boolean True or False 4 > 3

### String Concat­enation

 A method for combining strings `print(­"­Hel­lo" + " World!­")`

### Type Casting

 A method for changing the data type of a value `price = 2.00` `print(­"The apple is " + str(price) + "­dol­lar­s")`

### Type Cast Functions

 str() converts a value to a string int() converts a value to an integer float() converts a value to a float bool() converts a value to a boolean

### Basic Mathem­atical Operators

 + Addition - Subtra­ction * Multip­lic­ation / Division

### Example of Mathem­atical Operations

 ``````num1 = 5 num2 = 3 product = num1 * num2 print("Product:" + str(product))``````

### Condition

 an expression that uses relation operators and is either True or False also known as a boolean expression

### Relational Operators

 == Checks if the values are equal != Checks if the values are not equal > Checks if the left value is greater than the right value < Checks if the left value is less than the right value >= Checks if the left value is greater than or equal to the right value <= Checks if the left value is less than or equal to the right value

### If statement

 used to run instru­ctions when the condition is True ` if grade >= 90:  print("Letter grade: A")`

### If-else statement

 used to run instru­ctions when the condition is True and when the condition is False ` if grade >= 90:  print("Letter grade: A")` ` else:  print("You did not get an A")`

### If-elif

 used to run instru­ctions when multiple conditions are met ` if grade >= 90:  print("Letter grade: A")` ` elif grade >= 80:  print("Letter grade: B")` ` else:  print("Letter grade: unknow­n")`

### For Loop

 used to repeat a set of instru­ctions for a sequence of values `grade_list = [88,90­,68­,78­,89­,96­,10­0,40]` `for grade in grade_­list:` ` ­ ­pri­nt(­grade)`' prints each grade in grade_list

### range(­stop)

 is a function that returns a sequence of numbers starting from 0 to stop-1. `for x in range(6):` ` ­ ­pri­nt(x)` prints x when x is 0, 1, 2, 3, 4 and 5

### range(­start, stop)

 is a function that returns a sequence of numbers starting from start to stop-1. `for x in range(1, 6):` ` ­ ­pri­nt(x)` prints x when x is 1, 2, 3, 4 and 5

### range(­start, stop, step)

 is a function that returns a sequence of numbers starting from start to stop-1 while increasing by step. `for x in range(1, 6, 2):` ` ­ ­pri­nt(x)` prints x when x is 1, 3 and 5