Common Python Errors

Common Python Errors

by Boxplot    Sep 1, 2019   
This post is updated as appropriate, so keep checking back!
Table of Contents

Errors when installing python with homebrew Errors when writing/running python code

Installing Python

Error: Permission denied @ dir_s_mkdir – /usr/local/Frameworks

Check out this article for help:  

Error: Could not symlink bin/2to3

Check out this article for help:

Writing Python Code

TypeError: Can’t convert …

This means one of a few things:
  1. That you are trying to combine data types that aren’t compatible. You can’t concatenate a string and an integer for example.
  2. You’re trying to perform some operation on the wrong datatype for that function.

NameError: global name ‘—‘ is not defined

Did you forget to put something in quotes? Remember if you didn’t define something as a variable, list, dictionary, etc. previously, and it’s not a number, it needs to be in quotes!  

IndentationError: expected an indented block

There are several types of indentation errors. These are pretty self-explanatory. You either forgot an indent or have too many. Remember, python considers indents to be four spaces or a tab, exactly.  

SyntaxError: invalid syntax

This could mean a lot of things, but basically you aren’t following one of the basic syntax rules of Python. Here are some common examples:
  • Forgetting the parens around the arguments to print
  • Forgetting the colon at the end of the condition in an if statement, or in a for loop
  • Trying to use a reserved word as a variable name
  • Code like: if my_variable = 8: (should be == 8 when in an IF statement!)

IndexError: list index out of range

Typically this means you are trying to access an item in a list that doesn’t exist. For example, : flowers = ["rose", "tulip", "daisy"] print("Flowers in my garden are:", flowers[1], flowers[2], flowers[3]) There is no flowers[3]! Remember, lists start at 0, so it should have been flowers[0], flowers[1], flowers[2].  


These seem scary, but they are similar to the NameError, only specific to dictionaries. They are raised when a key is not found in the set of existing keys. Check for spelling and case sensitivity!  


This is most commonly caused by trying to convert a bad string into a number. For example: my_num = int("Word").

"Tables & Linking Data Structures in Excel"

"Population Mean Hypothesis Test Example"

Need help applying these concepts to your organization's data?

Chat with us about options.

Schedule a Meeting   

Continue to make data-driven decisions.

Sign up for our email guides that contains relevant tips, software tricks, and news from the data world.

*We never spam you or sell your information.

Back to Top