Fossman Media | Python

Shebang (local)

If the script is being run locally on the machine that created it, the following command can be use to find the path to the Python interpreter. After finding the path, add it to the shebang/hashbang at the top of the script.

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Find path to interpreter

Shebang (portable)

Use the following example to specify the intended interpreter by the environment variable. This can be useful if the path to the interpreter is unknown.

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Using environment variable

Basic User Input

The following example uses a user input to get information from the user. Ater this information has been collected, it will be stored in a variable called any_value and shown to the user.

#!/usr/bin/python3

import sys

# user input
any_value = input('Enter any value: ')

# print out entered value
print ('value entered: ' + any_value)

# exit this script
sys.exit()

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User input example

if / else

The following is an example scipt using a if/else statement. The user will first be asked to select a mode. If read is selected the message "mode was set to read" will be shown. If any other value is entered, the message "mode was not set to read" will be shown.

#!/usr/bin/python3

import sys

# user input
mode = input('choose mode [read/write]: ')

# if / else
if mode == 'read':
    print('mode was set to read')
else:
    print('mode was not set to read')

# exit this script
sys.exit()

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if/else statement example

else / if

The following is an example scipt using a else/if statement. The user will first be asked to select a mode. If read is selected the message "mode was set to read" will be shown. If write is selected the message "mode was set to write" will be shown. If any other value is entered, the message "invalid value" will be shown.

#!/usr/bin/python3

import sys

# user input
mode = input('choose mode [read/write]: ')

# else / if
if mode == 'read':
    print('mode was set to read')
elif mode == 'write':
    print('mode was set to write')
else:
    print('invalid value: ' + mode)

# exit this script
sys.exit()

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else/if statement example

if / and

The following is an example scipt using a if/and statement. The user will first be asked to provide a username and password. If the username is root and the password is password, they will be presented with a welcome message. If the username entered is root and the password is not password, they will get a message saying the password is invalid. Finally... if the user is not root, they will be denied access and threatened.

#!/usr/bin/python3

import sys

# user input
print('')
username = input('Username: ')
password = input('Password: ')

# if / and
if username == 'root' and password == 'password':
    print('\nWelcome ' + username)
elif username == 'root' and password != 'password':
    print('\npassword entered is not valid')
else:
    print('\nonly root has access')

# exit this script
sys.exit()

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if/and statement example

if / or

The following is an example scipt using a if/or statement. The user will first be asked to provide a username and password. If the username is root or tux and the password is password, they will be presented with a welcome message. If the username entered is root or tux and the password is not password, they will get a message saying the password is invalid. Finally... if the user is not root or tux, they will be denied access and threatened.

#!/usr/bin/python3

import sys

# user input
print('')
username = input('Username: ')
password = input('Password: ')

# if / or
if (username == 'root' or username == 'tux') and password == 'password':
    print('\nWelcome ' + username)
elif (username == 'root' or username == 'tux') and password != 'password':
    print('\npassword entered is not valid')
else:
    print('\nonly root and tux have access')

# exit this script
sys.exit()

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if/or statement example

For Loops

The following code snippets are examples of for loops

Specified Range
Complete a task for a predetermined amount of iterations. In the example below... the sentence "just some text" will be printed out to the screen 10 times.

#!/usr/bin/python3

import sys
import time

for i in range(10):
    print('just some text')
    time.sleep(1)

# exit this script
sys.exit()

Specified Range (iterations shown)
Similar to the example above, the following code snippet will complete a task for a predetermined amount of iterations. The sentence "just some text" will be printed out to the screen 10 times. Showing each iteration can be done by adding the variable created in the for loop "i" to the end of the print function. In this context, the "i" can be considered as an item or iteration. Any other character or name can also be used, as the "i" is only representative. str(i) is used to convert this value into a string so it can be printed out to the screen.

#!/usr/bin/python3

import sys
import time

for i in range(10):
    print('just some text: ' + str(i))
    time.sleep(1)

# exit this script
sys.exit()

Specified Iterations (iterations shown)
In this example, we can define where the iteration will start and where it will end. Each iteration will be shown, starting at 1 and ends at but not including 10.

#!/usr/bin/python3

import sys
import time

for i in range(1, 10):
    print('just some text: ' + str(i))
    time.sleep(1)

# exit this script
sys.exit()

Specified Iterations (iterations shown 5-10)
Similar to the example above, we can specify where the iterations will start and when they will end. In this example the 1st iteration starts at 5 and ends at but not including 10. Resulting in 5 iterations.

#!/usr/bin/python3

import sys
import time

for i in range(5, 10):
    print('just some text: ' + str(i))
    time.sleep(1)

# exit this script
sys.exit()

Specified Iterations (iterations shown 1, 4, 7 and 10)
In addition to specifying where the iterations will start and end, we can also specify the size of each step. In the example below, the iterations will start at 1, ends at but does not include 10 and will have a step count of 3. Resulting in 3 iterations (1,4,7)

#!/usr/bin/python3

import sys
import time

for i in range(1, 10, 3):
    print('just some text: ' + str(i))
    time.sleep(1)

# exit this script
sys.exit()

Lists (show contents)
For loops can also be used to iterated through a list. The items in said list can be anything from strings to functions and even other lists. In the example below, a list of employees will be printed out to the screen from an list of employees.

#!/usr/bin/python3

import sys
import time

Employees = ['John', 'Alice', 'Tux', 'May', 'Jessie', 'Jade', 'Louis', 'Sara', 'Donald']

print('')
print('Employees' + '\n---------')

for i in Employees:
    print(i)
    time.sleep(1)

# exit this script
sys.exit()

While Loops

The following is an example script using a while loop. These are used to execute a block of code repeatedly while a specified condition remains true. It evaluates the condition before each iteration based on changing conditions within the program.

While Loop (Basic Example)
In the example below, the while loop will execute its commands while a condition remains True or when the iteration count reaches 5. After which, the script will then exit. Each iteration will be shown excluding the last iteration(5).

#!/usr/bin/python3

import sys
import time

count = 1

while True:
    print('current count: ' + str(count))
    count = int(count)
    count += 1
    time.sleep(1)
    if count == 5:
        break

# exit this script
sys.exit()

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basic while loop

While Loop (with user input)
In the example below, the while loop will execute its commands while the value of "guess" is not equal to 5 (the magic number) At each iteration, the user will be prompted to enter a number. When the magic number has been guessed correctly the number will be shown along with some positive feedback. After which, the program will exit.

#!/usr/bin/python3

import sys

magic_number = '5'
guess = '0'

while guess != magic_number:
    guess = input('Guess the magic number [1-10]: ')

print('\nYou guessed correctly!')
print('The magic number is ' + magic_number)

# exit this script
sys.exit()

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while loop with user input