Problem scenario
You are running a Python script. You keep getting “SyntaxError: invalid syntax” and a line number. You can find nothing wrong with the syntax on the specified line number. What do you do?

Possible solution #1
Look at the line with code, as opposed to blank line(s), above it. Is there a missing quote, brace, bracket or parentheses?

Possible solution #2
Are you trying to use an “if” statement on one line?

…

Continue reading “How Do You Troubleshoot “SyntaxError: invalid syntax” in Python?”

Problem scenario
You have a list in Python that you copy into another variable. You change the original list and the copied version changes. Why does the copied version get copied and what can you do to overcome this?

Solution
There is something called a “deep” copy and a “shallow” copy. This program will illustrate both the problem and the solution:

list_a = [3, …

Continue reading “Why in Python Does a Variable Copy Get Changed when You Change Its Source?”

Problem scenario
You want to use the copy feature in Python. What do you do?

Solution
To see the different types of copying, use a mutable object such as a list. Here is an example:

import copy

var1 = [1, 2, 3, 4]
shallow_copy = var1
deep_copy = copy.deepcopy(var1)
var1.append(999999999999)

print()
print(shallow_copy)
print(” — Shallow copy above and deep copy below —.”)
print(deep_copy)

For most (or perhaps all) intents and purposes,

…

Continue reading “How Do You Use the .copy() Feature in Python?”

Problem scenario
You know that Python has a feature for documentation strings that can print out when your program runs. How does it work as comments and as something that is displayed at the time the code is executed?

Solution
To best illustrate how one works, create a file called test.py with this code and run it:

def cool_function(n):
”’This is an example of a docstring. …

Continue reading “How Does a Python Docstring Work?”

Question
You have seen messages when coding in Python about iterable and subscriptable. What is the difference between these two?

Answer
A subscriptable does not necessarily use the iter method, but an iterable always does.

A subscriptable object in Python leverages the getitem() method, but it may or may not use the iter method.

…

Continue reading “What Is The Difference between Iterable and Subscriptable in Python?”

Problem scenario
You want to display a specific number of places after the decimal (e.g., one, two or three) with numeric values in Python. You want the decimal value to be rounded if it is too long. How do you always show (including trailing zeroes) a specific number of places to the right of the decimal point?

Solution
This Python 3 program will illustrate how:

x=123.45678
y=”{:.3f}”.format(x)
print(y)

a=123
b=”{:.1f}”.format(a)
print(b) …

Continue reading “How Do You Display a Fixed Number of Numbers after the Decimal Point in Python?”