Cheatography
https://cheatography.com
Input & Output
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Output a message to the user print("Hello There")
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Ask the user for a text input (string) name = input("What is your name?")
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Ask the user for a number input (Integer) age = int(input("How old are you?"))
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Add a new line name = input("What is your name?\n")
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Concatenate strings print("Hello "+ name )
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Concatenate different data types print("You are",age ,"years old")
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Output the first letter print(name[0])
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Uppercase/Lowercase format print(name.upper()) | print(name.lower())
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Uppercase then lowercase format print(name[0].upper()+name[1:].lower())
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IF Statements
IF
x = 3
if x == 3:
print("x = 3")
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IF / ELSE
x = 7
if x > 8:
print("Yes")
else:
print("No")
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ELIF
x = 4
if x > 8:
print("A")
elif x > 5:
print("B")
elif x > 2:
print("C")
else:
print("F") |
Remember to indent your code [Press the 'Tab' button n the keyboard]
Editing Lists
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Replace third item mylist[2] = 43
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Insert in position mylist.insert(1, "OCR")
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Add to the end of a list mylist.append("GCSE")
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Remove all Sciences mylist.remove("Science)
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Delete all items mylist = []
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Delete third item del mylist[2]
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Reverse list order mylist.reverse()
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Sort list order mylist.sort()
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Join items using a space print(" ".join(mylist))
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Dictionaries
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Creating a dictionary mydict = {"a":1, "b":2, "c":3}
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Returns the value of b mydict["b"]
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Check in dictionary "c" in mydict
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Display the keys mydict.keys()
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Display keys and items mydict,items()
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Inequalities
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Equal to x == 3
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Not equal to x != 4
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Less than / equal to x <= 2
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More than / equal to x >= 1
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Between two numbers <= 3 x <= 12
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AND x == 1 and z == 4
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OR x == "A" or x == "a"
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For Loop
Repeat 5 times
for x in range (5):
print("Owen")
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Repeat length of string
for x in "Nathan":
print(x)
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Count from 1 to 10
for x in range (1,11):
print(x)
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Count from 1 to 10 in 2's
for x in range (1,11,2):
print(x) |
Repeats code a predefined number of times
While Loops
Repeat until false
while True:
print("Hello There!")
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Using 'break' to end the loop
while True:
x = input("Say Yes")
if x == "Yes":
break
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Until x is more than 100
x = 0
while x < 100:
x = int(input("x ?")) |
A while loop will repeat infinitely until the program or user input tells it to stop
Repeats code until a condition is met [within the program]
Creating And Using Files
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Create document myfile = open("Filename.txt","w")
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Add data to the text file myfile.write("Hello World")
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Reads entire file into one string myfile.read()
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Reads first 4 characters into one string myfile.read(4)
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Reads one line of a file myfile.readline()
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Reads entire file into a list of strings, one per line myfile.readlines()
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Steps through lines in a file for eachline in myfile:
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Close the file myfile.close()
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("w" write, "r" read, "a" append)
.csv will create a spreadsheet
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Demonstrating knowledge
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Annotate / Comment on a line of code #short comments
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Annotate / comment on a block of code '''for longer comments'''
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Variables
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Creating a variable name = "Josh"
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Length of string len(name)
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Print a variable print(name)
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Coverting [String↔Integer] str(age) 'or' int(age)
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All variables are strings [str] by default
Numbers
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Addition 2+2
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Subtraction 4-1
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Multiplication 3*5
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Division 15/10
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To the power of... 1.5**2
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Multiplying A String "Ethan" *14
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Numbers follow the BIDMAS / BODMAS rule
Creating And Accessing Lists
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Creating a list mylist = ["Computer", "Science", 17]
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Output full list print(mylist)
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Access first item mylist[0]
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Access first to second mylist[1:2}
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Access third item to the end mylist[2:]
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Access up to the third item mylist[:2]
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Check for in list "Computer" in mylist
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Concatenate mylist + ["a"]
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Remove third item and use mylist.pop(2)
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Remove last item and use mylist.pop()
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Find position in the list mylist.index(Science)
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Count appearances mylist.count(17)
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Add values sum(mylist)
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Length of List len(mylist)
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Compare lists cmp(mylist, list)
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Biggest number in list max(mylist)
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Smallest number in list min(mylist)
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