Python is an open-source and versatile programming language used by thousands of web developers, data scientists, and software engineers. It is very popular because it has extensive support libraries, user-friendly data structures, and a vibrant support community.
This Python Cheat Sheet can serve as a quick reference for system administrators and network administrators.
We include all essential categories and items including: network programming libraries, keywords, variables and data types, strings, lists, and more.
Basic Python Libraries for Network Admin
Here is the list of basic Python libraries with a brief explanation.
|PIP||Package manager for Python.|
|pypcap||Python interface to pcap a packet capture library.|
|PyPI||Repository of open-source Python packages.|
|Paramiko||It is a Python interface around SSH networking concepts.|
|EDDIE Tool||Python agent used for system and network monitoring, security, and performance analysis.|
|pycos||It provides an Asynchronous Socket class to convert Python's blocking socket to a non-blocking socket.|
|Diesel||Framework to write reliable and scalable network applications in Python.|
|Celery||It is a task queue implementation for Python web applications to asynchronously execute work outside the HTTP request-response cycle.|
Python has a set of keywords (or reserved words) used to define the syntax of the coding. You can not use these words as identifiers, functions, or variable names. Here is a list of such keywords with examples.
|False, True||Boolean value, result of comparison operations||False == (1 > 2), True == (1 < 2)|
|and, or, not||Logical operators||x, y = True, False
(x or y) == True # True
(x and y) == False # True
(not y) == True # True
|break||Ends loop prematurely||while(True):
print (“Hi How R U?”)
|continue||Finishes current loop||while(True):
|Defines a new class
Defines a new function
self.content = 1.0
self.content = 0.0backs = Bear()
|if, elif, else||Used for a conditional program that starts with if, tries the elif, and finishes with else.||x = int(input(“type your value: “))
if x > 4: print(“Big”)
elif x == 4: print(“Medium”)
|for, while||for a in [0,1,2,3]:
print(a)b = 1
while b < 4:
b = b + 1
|in||Checks whether element is in sequence.||30 in [10, 30, 40, 70] # True|
|is||Checks whether both elements point to the same object.||a = b = 5
a is b # True
 is  # False
|None||Empty value constant||def f():
a = 3
f() in None # True
|lamda||Function with no name||(lamda a: a + 4)(4) # returns 8|
|return||Terminates execution of the function and passes the flow of performance to the caller.||def incrementor(a):
return a + 1
incrementor(3) # return 4
In Python programming, everything is an object. Every value in Python is called an “object,” and every object has a specific data type.
There are various data types in Python. Some of the essential types are listed below:
- int An integer number that represents an object or number such as 3, 4, 5, etc.
- float Represents ‘floating-point numbers' such as 0.5, 1.25, 2.0, etc.
- Strings A collection of one or more characters put in a single quotes, double-quotes, or triple quotes.
|Numeric Types||int, float, complex|
|Sequence Types||list, tuple, range|
|Set Types||set, frozenset|
|Binary Types||bytes, bytearray, memoryview|
Math operators in Python perform mathematical operations like addition, subtraction, multiplication, and division. Here we list all of the math operators with explanations and examples.
|**||Exponent||3 ** 2 = 9|
|%||Modulus/Remainder||22 % 8 = 6|
|//||Integer division||20 // 8 = 2|
|/||Division||22 / 8 = 2.75|
|*||Multiplication||2 * 3 = 6|
|–||Subtraction||8 – 2 = 6|
|+||Addition||2 + 8 = 10|
|!=||Not equal to|
|>=||Greater than or Equal to|
|<=||Less than or Equal to|
Network Services in Python
There are two levels of network services in Python.
- High-level access This service helps programmers access the application-level network protocols.
- Low-level access This service allows you to access the socket support for the operating systems by using Python libraries. You can use low-level access to implement connection-less and connection-oriented protocols for performing network programming.
There are several methods available that help network administrators manage the connections. Some of them are listed below.
|listen()||Used to establish and start TCP listeners.|
|bind()||Used to bind-address to the socket.|
|connect()||Used to make a connection with the TCP server.|
|accept()||Used to accept TCP client connection, waiting until a connection arrives.|
|recv()||Used to receive TCP messages.|
|close()||Used to close a socket.|
|Send()||Used to send messages.|
|socket.gethostname()||Used to retrieve the hostname.|
|mysocket.accept()||Returns a tuple with the remote address that has connected.|
|mysocket.bind( address )||Used to attach the specified address to the socket.|
|mysocket.getpeername()||Used to get the remote address where the socket is connected.|
|mysocket.connect( address )||Used to assign the data sent through the socket to the given remote address.|
|mysocket.getsockname()||Used to retrieve the address of the socket’s local endpoint.|
|Used to obtain port number using the domain name.|
|Used to check support for IPV6.|
|ipaddress.ip_address(‘192.168.0.1')||Used to assign an IP address.|
|ipaddress.ip_network(‘192.168.0.1/24')||Used to determine the IPv4 or IPv6 version.|
|Used to obtain the network from an interface.|
|Used to find the number of IP addresses in the specified network.|
|Used to find the netmask of the specified IP address.|
Python Internet Modules
Here is the list of all Python internet modules.
|Gopher||Used to transfer documents.||70||Gopherlib, urllib|
|Telnet||Used to open a command line on a remote computer.||23||telnetlib|
|IMAP4||Used for fetching emails from the mail server.||143||impalib|
|POP3||Used for fetching emails from the mail server.||110||poplib|
|SMTP||Used for sending emails.||25||smtlib|
|FTP||Used for file transfers.||20||Ftblib, urllib|
|HTTP||Used to access web pages over the internet.||80||Httplib, urllib|
We've included all useful Python commands, libraries, and code that you can use as a quick reference in the above guide. Feel free to let us know in the comments if you have any questions.