Problem scenario
You want to know how remove is different from pop when manipulating a list in Python. What should you do?
Solution
Here are four facts which should help elucidate the differences.
- The remove keyword searches for a matching item in the list — not by its indexed, integer value; then the first matching item is removed.
…
Continue reading “In Python How Is the List Function “remove” Different from “pop”?”
Problem scenario
In your PHP program, the Python binary is executing regardless of how the PHP program is run (e.g., from a command line with the php command or when downloaded from a web browser). The PHP program will launch Python programs if the PHP program is invoked from the back-end with PHP. But Python programs are not being interpreted by Python when a web browser loads the PHP file.
…
Problem scenario
You have a Python program that works, but you get an error when you run it. You get a message like this: “NameError: global name ‘var2’ is not defined”
Here is your source code:
def fun1(var1):
print(“this is how it works”)
var1 = var2
return var2
b = fun1(“check it out”)
print(b)
What should you do about this error?
Solution
A variable inside a function must be defined.
…
Problem scenario
You want to retrieve VPC peering connection info and other VPC info via Boto3. With Python 3 you tried to run this Python 2 (and Boto 2.x) program:
import boto.vpc
c = boto.vpc.connect_to_region(‘us-east-1’)
vpcs = c.get_all_vpcs()
vpc_peering_connection = c.create_vpc_peering_connection(vpcs[0].id, vpcs[1].id)
(It was written by the person who developed Boto 2.x here.)
You have a variety or problems with the syntax not working.
…
Continue reading “How Do You Get Past “ImportError: No module named ‘boto’”?”
Problem scenario
You want to install pip on an Ubuntu/Debian Linux server. What do you do?
Solution
Run this command:
sudo apt -y install python3-pip
…
Continue reading “How Do You Install pip on Ubuntu/Debian Linux?”
Problem scenario
You have a camera (e.g., a TCP/IP ADT security camera) attached to your a router on the network with your laptop. You know the camera’s MAC address by looking at the back of the camera itself (or you know its IP address on your network which is even more helpful). How do you use this camera over the network?
Solution
1.
…
Continue reading “How Do You Configure the Wireless Security Camera with a TCP/IP Network?”
Problem scenario
You see two underscores or two underbars before a function in Python. What does this syntax signify?
Possible Solution #1
The answer is best explained by running this program once with no modification and a second time with a modification.
class ContintClass():
def __init__(self):
self.__completelyprivate = “1111111111”
self._semiprivate = “2222222”
foo = ContintClass()
#print(foo.__completelyprivate)
print(“Above is an attempt to print a completely private data member of an object”)
print(“Below is an attempt to print a semi-private data member of an object”)
print(foo._semiprivate)
Before you run the program the second time,
…
Problem scenario
You have a Python program with print statements. When you run the program, you get twice as many print statements as you expect. What could be wrong?
Possible Solution #1
Do not name the program re.py or string.py. When you name the program re.py and have an import re statement, Python may print every line it is supposed to print twice.
…
Continue reading “Why is Your Python Programming Printing Duplicate Lines?”
Problem scenario
You want to create a .txt file that has 50 key-value pairs. You want the keys to be whole numbers. You want the values to be five-character strings. What should you do?
Solution
import random
import string
import sys
def randomword(length):
letters = string.ascii_lowercase
return ”.join(random.choice(letters) for i in range(length))
def printer(counter, webstera):
webstera[counter] = randomword(5)
if (counter < …
Continue reading “How Do You Write a Python Program to Create a .txt File with 50 Key-Value Pairs?”