IndentationError: expected an indented block – Python

The occurrence of the “IndentationError: expected an indented block” error signals a coding issue involving improper indentation within the code block. This error commonly arises due to a combination of tabs and spaces being utilized inconsistently. The anticipated indentation is essential within a designated code block. “IndentationError: expected an indented block” emerges when a mixture of spaces and tabs is employed for indentation in the code. Properly defining a code block allows for flexible indentation levels, but it is crucial to maintain precise alignment to ensure they are at the same level.

The Python IndentationError: expected an indented block issue arises when neglecting to properly indent statements within a compound statement or a user-defined function. This Python error is triggered by an inconsistent mixture of tabs and spaces. Failure to include appropriate indents in compound statements and user-defined functions results in the IndentationError: expected an indented block error being raised. Ensure precise indentation to rectify this issue in Python coding practices.

The indentation in programming, often referred to as the distance or count of empty spaces between the beginning of a line and the left margin, serves the purpose of enhancing code readability and visual structure. In Python, indentation is crucial for defining the structure of compound statements and user-defined functions. Proper indentation not only contributes to the aesthetic presentation of code but also plays a pivotal role in conveying the logical organization of the program.

Exception

File "/Users/python/Desktop/test.py", line 5
    print "hello world";
        ^
IndentationError: expected an indented block
[Finished in 0.0s with exit code 1]

Root Cause

Python is a language that places a high importance on indentation. Compound statements and functions necessitate an indentation at the beginning of a line. The error, IndentationError: expected an indented block, is triggered when there is a missing indent in the line where the Python interpreter anticipates it.

It’s important to note that this error does not signify a syntax or semantic flaw in your code. Instead, it is indicative of a stylistic issue in the program’s writing style, underlining the significance of adhering to Python’s indentation conventions for proper execution.

Solution 1

This error is commonly caused by a combination of spaces and tabs in your code. Ensure uniformity in your program’s indentation style by using either spaces or tabs consistently. Modern Python Integrated Development Environments (IDEs) often provide options to convert tabs to spaces or vice versa. Review and select the appropriate setting in your Python IDE to facilitate the conversion and alignment of indentation.

By adhering to a consistent indentation format, whether it be spaces or tabs, you can effectively resolve this error. Choose the format that suits your preference and aligns with your coding style for a seamless resolution of the issue.

Solution 2

To resolve the error in Sublime Text Editor, follow these steps:

1. Open your Python program in Sublime Text Editor.
2. Select the entire Python code, including white spaces, by pressing “Ctrl + A.”
3. Notice the display of tabs as continuous lines and spaces as dots in the program.
4. Choose your preferred format, whether tabs or spaces, and maintain uniformity throughout the code.
5. Modify the indentation format across the entire codebase.

By adhering to a consistent indentation style, either tabs or spaces, you will effectively address the IndentationError: expected an indented block error in your Python code. This ensures that your code follows a unified formatting standard.

Program

a=10;
b=20;
if a > b:
	print "Hello World";      ----> Indent with tab
        print "end of program";    ----> Indent with spaces

Solution

a=10;
b=20;
if a > b:
	print "Hello World";      ----> Indent with tab
	print "end of program";    ----> Indent with tab

Solution 3

The absence of proper indentation in the code where expected by the Python interpreter can lead to issues. It’s crucial for blocks within the program to feature indentation at the beginning of each line. In the given example, it’s recommended to add indentation at line 4 to ensure code correctness.

Program

a=20;
b=10;
if a > b:
print "hello world";

Output

File "/Users/python/Desktop/test.py", line 5
    print "hello world";
        ^
IndentationError: expected an indented block

Solution

a=20;
b=10;
if a > b:
	print "hello world";

Output

hello world
[Finished in 0.0s]

Solution 4

Python might encounter an incomplete block of statements, possibly due to missing statements or incomplete / removed lines within the program. Such situations can trigger an indentation error.

To rectify this, it’s advisable to add the missing lines to the program or finalize any pending programming tasks. This corrective action will effectively resolve the error, ensuring the completeness and accuracy of the code.

program

a=20;
b=10;
if a > b:
	print "hello world";
else:

Solution

a=20;
b=10;
if a > b:
	print "hello world";
else:
	print "hello world in else block";

Output

hello world
[Finished in 0.0s]

Solution 5

In the provided program, if the else block lacks relevance to the logic, consider removing it to resolve potential indentation errors. Leveraging the Python interpreter proves beneficial in code correction. To ensure optimal code quality, eliminate any unnecessary code segments within the program. This proactive approach enhances code clarity and prevents issues related to indentation errors.

Program

a=20;
b=10;
if a > b:
	print "hello world";
else:

Output

File "/Users/python/Desktop/test.py", line 5
    print "hello world";
        ^
IndentationError: expected an indented block

Solution

a=20;
b=10;
if a > b:
	print "hello world";

Output

hello world
[Finished in 0.0s]

Solution 6

While examining the Python program, meticulously review the indentation within compound statements and user-defined functions, as adhering to the correct indentation can be a meticulous task in the source code. Python offers a solution for identifying and rectifying indentation errors by indicating the specific line causing the issue. To diagnose the problem, execute the following Python command, which will pinpoint and display the actual indentation error, aiding in swift resolution.

Command

python -m tabnanny test.py 

Example

$ python -m tabnanny test.py 
'test.py': Indentation Error: unindent does not match any outer indentation level (<tokenize>, line 3)
$ 

Solution 7

Another approach to pinpointing an indentation error is by utilizing the command prompt in Windows OS or the terminal command line window on Linux or Mac. Initiate the Python interpreter, and by entering the “help” command, the error in the Python program will be displayed, aiding in the identification and resolution of the indentation issue. This method provides an alternative means to efficiently address and rectify any indentation errors in your Python code.

Command

$python
>>>help("test.py")

Example

$ python
Python 2.7.16 (default, Dec  3 2019, 07:02:07) 
[GCC 4.2.1 Compatible Apple LLVM 10.0.1 (clang-1001.0.37.14)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> help("test.py")
problem in test - <type 'exceptions.IndentationError'>: unindent does not match any outer indentation level (test.py, line 3)

>>> 
Use exit() or Ctrl-D (i.e. EOF) to exit
>>> ^D