Python for hacking latest

 

                                                                           Python for hacking

Build in functions:

Print(x, sep=’y)     -    Prints x objects separated by y

Input(s)  -  prints s and waits for an input that will be returned

Len(x) - returns the length of x (s, L or D)

Min(L) -  returns the minimum value in L

Max(L) - returns the maximum value in L

Sum(L) - returns the sum of the values in L

Range(n1,n2,n) – returns a sequence of numbers from n 1 to n2 steps of n\

Abs(n) -returns the absolute value of n

Round (n1,n)  - returns the n 1 number rounded to n  digits

Type(X) -returns the type of x (string, float, list, dict…)

Str(x)  - converts x to string

List(X) converts x to a list

Int(x)  - converts x to a integer number

Float(X) - converts x to a float number

Help(s) -   print help about x

Map (function, L) - Applies function to values in L

 

 

Conditional statement:

If < condition>:

<code>

Else if <condition>:

<code>

…

Else:

<code>

If<value> in <list>:

Data Validation:

Try:

<code>

Expect <error>:

<code>

Else:

<code>

 

Working with files and folders:

Import os

Os.getcwd()

Os.makedirs(<path>)

Os.listdir(<path>)

 

Loops:

While <condition>:

<code>

For<variable> in <list>:

                <code>

For<variable> in

Range(start,stop,step):

                <code>

For key, value in

Dict.items():

                <code>

Loops control statements:

Break    -              finishes loop execution

Continue             -              jumps to next iteration

Pass       -              does nothing

Running external programs:

Import os

Os.system(<command>)

 

Function:

def function(<params>):

                <code>

                Return<data>

Modules:

Import module

Module.function()

From module import *

Function()

Reading and writing files:

F= open(<path>, ‘r’)

f.read(<size>)

f.readline(<size>)

f.close()

f = open(<path>,’r’)

for line in f:

                <code>

f.cloase

f=open(<path>,’w’)

f.write(<str>)

f.close()

 

Variables + Strings:

#Hello world

Print(“HELLO world”)

#Hello world with a variable

Msg = “Hello world!”

Print(msg)

 

#Concatenation (combining strings)

First_name = “hack”

Last_name =” Einstein”

Full_name = first_name + “” + last_name

Print(full_name)

 

Dictionaries:

#A simple dictionary

Person = { “age”: “21”, “gender”: “female”}

# Accessing a value

Print (“The person’s age is “+ person[“age”])

#Adding a new key-value pair

Person[“height”] = 170

#Looping through all key-value pairs

Ages = { “Stacy”; 20, “ Michelle”; 21}

For name, age in ages.Items():

                Print (name + ”is” + str(age))

#Looping through all keys

Ages = {“Stacy”: 20, “ Michelle”: 21}

For name in ages.key():

                Print (name + “is a name”)

#Looping through all the values

Ages = {“Stacy”: 20, “Michelle”: 21}

For age in ages.values();

               Print(str(num) + “is my age”)

Lists:

#Make a list

Colors = [“red”, “green”, “blue”]

#Get the first item in a list

First_color = colors[0]

#Get the last item in a list

Last_color = colors[-1]

#Looping through a list

For color in colors:

                Print(color)

#Adding items to a list

Colors   =             []

Colors.append(“red”)

Colors.append[“green”)

Colors.append(“blue”)

#Making numerical lists

Flag =[]

For x in range (1,12):

                Flag.append(x**2):

#List comprehensions

Flag = [x**2 for x in range(1, 12)]

#Slicing a list

Hackers = [“janathan”, “ loryn”, “kim”]

First_two = hackers [:2]

#Copying a oist

Copy_of_hackers = hackers[:]

 

User Input:

#Prompting for a value

Name = input (“what’s your name?”)

Print (“Hello, “ +name+ “!”)

#Prompting for numerical input

Age = input (“How old are you?”}

Age = int (age)

Pi = input (“What is the value of pi?”)

Pi = float(pi)

 

IF Statements:

# Conditional tests

Equals                   h == 10

Not equal            h !=10

Greater than      h > 10

Or equal to         h>=10

Less than             h < 10

Or equal to         h <=10

#Conditional test with lists

“red” in colors

“green” not in colors

#Assigning Boolean values

Is_active              =             True

Can_enter          =             False

#A simple if test

If age >= 21:

                Print (“you can have marriage!”)

#if-elif-else statements

If age< 13:

                Person = “child”

Elif age< 20:

                Person = “teenager”

Else:

                Person = “adult”

 

Tuples:

#Making a tuple

Couple = [“bonnie”, “ clyde”]