Python Archives

Python TypeError: ‘NoneType’ object is not iterable Solution

With Python, you can only iterate over an object if that object has a value. This is because iterable objects only have a next item which can be accessed if their value is not equal to None. If you try…

Python Queue and Deque: A Step-By-Step Guide

Python queue is a built in library that allows you to create a list that uses the FIFO rule, first in first out. Python deque uses the opposite rule, LIFO queue, or last in first out. Both operate on stacks…

Python Reverse List: A Step-by-Step Tutorial

You can reverse a list in Python using the built-in reverse() or reversed() methods. These methods will reverse the list without creating a new list. Python reverse() and reversed() will reverse the elements in the original list object. Reversing a…

Python NameError: name ‘self’ is not defined Solution

The value “self” is only available inside a method when a function is called and specified. You cannot access “self” in the arguments specified to a method, or inside a function without specifying “self” as an argument. Otherwise, you see…

Python ValueError: I/O operation on closed file Solution

You can only read from and write to a Python file if the file is open. If you try to access or manipulate a file that has been closed, the “ValueError : I/O operation on closed file” appears in your…

Python Find in List: A Beginner’s Guide

How do you find an item in a Python list? It’s a question all Python coders encounter at some point. Luckily, the language offers a number of ways in which you can find an item in a list, such as…

Python TypeError: ‘function’ object is not subscriptable Solution

Unlike iterable objects, you cannot access a value from a function using indexing syntax. Even if a function returns an iterable, you must assign the response from a function to a variable before accessing its values. Otherwise, you encounter an…

Python SyntaxError: non-default argument follows default argument Solution

An argument can have a default value in a Python function. If you specify arguments with default values, they must come after arguments without default values. Otherwise, you encounter a “SyntaxError: non-default argument follows default argument” error. In this guide,…

Python TypeError: ‘tuple’ object is not callable Solution

Tuples are enclosed within parentheses. This can be confusing because function calls also use parenthesis. If you use parentheses to access items from a tuple, or if you forget to separate tuples with a comma, you’ll encounter a “TypeError: 'tuple'…

Python TypeError: ‘float’ object not iterable Solution

Python can only iterate over an iterable object. This is a type of object that can return its members one at a time. If you try to iterate over a non-iterable object, like a floating-point number, you see an error…

Python TypeError: unhashable type: ‘dict’ Solution

The Python language is specific about what can be used as a key in a dictionary. In a Python dictionary, all keys must be hashable. If you try to use an unhashable key type when adding a key to a…

Python indentationerror: unindent does not match any outer indentation level Solution

Indenting your code can be a messy business if you try to use both spaces and tabs. In Python, using both methods of indentation results in an error. This error is “indentationerror: unindent does not match any outer indentation level”.…

Python ModuleNotFoundError Solution

Modules are integral to the Python language. Modules let you break down your code into multiple files. This helps maintain the readability and maintainability of a codebase. It’s common to encounter a ModuleNotFoundError when working with modules. In this guide,…

Python TypeError: not enough arguments for format string Solution

Python strings must be formatted using the correct number of arguments. When the number of arguments you specify is less than the number of values you want to format into a string, you encounter an error like “TypeError: not enough…

Python missing 1 required positional argument: ‘self’ Solution

Python classes need to be instantiated, or called, before you can access their methods. If you forget to instantiate an object of a class and try to access a class method, you encounter an error saying “missing 1 required positional…

Python typeerror: ‘>’ not supported between instances of ‘str’ and ‘int’ Solution

You can only compare items using mathematical operators if they have the same numerical data type. If you try to compare a string and an integer, you’ll encounter an error that says “not supported between instances of ‘str’ and ‘int’”.…

Python TypeError: ‘dict’ object is not callable Solution

Items in a Python dictionary must be called using the indexing syntax. This means you must follow a dictionary with square brackets and the key of the item you want to access. If you try to use curly brackets, Python…

Python takes 1 positional argument but 2 were given Solution

When you call a method associated with an object, there is one positional argument that is supplied by default: self. If you forget to include “self” when you define a method, you’ll encounter an error that says “takes 1 positional…

Python TypeError: string index out of range Solution

Like lists, Python strings are indexed. This means each value in a string has its own index number which you can use to access that value. If you try to access an index value that does not exist in a…

Python AttributeError: ‘str’ object has no attribute ‘append’ Solution

The append() method adds items to the end of a list. It cannot be used to add items to a string. Python returns an error stating “AttributeError: ‘str’ object has no attribute ‘append’” if you try to add values to…

Python TypeError: ‘int’ object is not callable Solution

Curly brackets in Python have a special meaning. They are used to denote a function invocation. If you specify a pair of curly brackets after an integer without an operator between them, Python thinks you’re trying to call a function.…

Python attributeerror: ‘list’ object has no attribute ‘split’ Solution

Python lists cannot be divided into separate lists based on characters that appear in the values of a list. This is unlike strings which values can be separated into a list. If you try to use the split() method on…

Rename Column in Pandas: A Beginner’s Guide

So you want to rename a column in a Python Pandas dataframe. Is that possible? Yes, it is. You use the rename() method to rename an individual column or the “columns” attribute to assign a new set of column headers…

Python typeerror: ‘str’ object is not callable Solution

Mistakes are easily made when you are naming variables. One of the more common mistakes is calling a variable “str”. If you try to use the Python method with the same name in your program, “typeerror: ‘str’ object is not…

Python SyntaxError: unexpected EOF while parsing Solution

Python is a statically typed language. This means it’s strict about how code is written. If you forget to complete a code block in your code, you get an error like “SyntaxError: unexpected EOF while parsing”. This happens in a…

Python TypeError: unsupported operand type(s) for -: ‘str’ and ‘int’ Solution

Integer values cannot be subtracted from string values and vice versa. This is because strings and integers are separate data types. If you try to subtract a string from an integer, you receive an error like “TypeError: unsupported operand type(s)…

Python local variable referenced before assignment Solution

When you start introducing functions into your code, you’re bound to encounter an UnboundLocalError at some point. This error is raised when you try to use a variable before it has been assigned in the local context. In this guide,…

Python IndexError: tuple index out of range Solution

Like lists, Python tuples are indexed. This means each value in a tuple has a number you can use to access that value. When you try to access an item in a tuple that does not exist, Python returns an…

Python ValueError: invalid literal for int() with base 10 Solution

Python is good at converting values to different data types. You can convert strings to integers, integers to strings, floats to integers, to name a few examples. There’s one conversion Python does not like: changing a float structured as a…

Python valueerror: too many values to unpack (expected 2) Solution

Python does not unpack bags well. When you see the error “valueerror: too many values to unpack (expected 2)”, it does not mean that Python is unpacking a suitcase. It means you are trying to access too many values from…

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