IndentationError: expected an indented block

The IndentationError: expected an indented block error indicates that you have an indentation error in the code block, which is most likely caused by a mix of tabs and spaces. The indentation is expected in an indented block. The IndentationError: expected an indented block error happens when you use both the spaces and tabs to indent in your code. The indent is expected in a block. To define a code block, you may use any amount of indent, but the indent must match exactly to be at the same level.

The python IndentationError: expected an indented block error occurs when you forget to indent the statements within a compound statement or within a user-defined function. In python, the expected an indented block error is caused by a mix of tabs and spaces. If you do not have appropriate indents added to the compound statement and the user defined functions, the error IndentationError: expected an indented block will be thrown.

The indent is known as the distance or number of empty spaces between the line ‘s beginning and the line’s left margin. The intent is used in order to make the code appear better and be easier to read. In python, the intent is used to describe the structure of the compound statement and the user-defined functions

Exception

In the compound statement and the user-defined functions, the inside code must be indented consistently. If you failed to add an indent, the error IndentationError: expected an indented block is shown. The error message suggests that the code lacks indentation.

The error IndentationError: expected an indented block is shown to be like the stack trace below. The error message displays the line that the indent is supposed to be added to.

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 the sentivite language of indentation. Compound statement and functions require an indent before starting a line. The error message IndentationError: expected and indented block is thrown due to a lack of indent in the line that the python interpreter expects to have.

There’s no syntax or semantic error in your code. This error is due to the style of writing of the program

Solution 1

In most cases, this error would be triggered by a mixed use of spaces and tabs. Check the space for the program indentation and the tabs. Follow any kind of indentation. The most recent python IDEs support converting the tab to space and space to tabs. Stick to whatever format you want to use. This is going to solve the error.

Check the option in your python IDE to convert the tab to space and convert the tab to space or the tab to space to correct the error.

Solution 2

In the sublime Text Editor, open the python program. Select the full program by clicking on Cntr + A. The entire python code and the white spaces will be selected together. The tab key is displayed as continuous lines, and the spaces are displayed as dots in the program. Stick to any format you wish to use, either on the tab or in space. Change the rest to make uniform format. This will solve the error.

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 program has no indentation where the python interpreter expects the indentation to have. The blocks are supposed to have an indentation before the beginning of the line. An indentation should be added in line 4 in the example below

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 may have an incomplete block of statements. There may be a missing statement in the block. Some of the lines may be incomplete or deleted from the program. This is going to throw the indentation error.

Add missing lines to the program or complete the pending programming. This is going to solve the error.

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 above program, if the else block is irrelevant to logic, remove the else block. This will solve the indent error. The Python interpreter helps to correct the code. Unnecessary code must be removed in the code.

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

In the python program, check the indentation of compound statements and user defined functions. Following the indentation is a tedious job in the source code. Python provides a solution for the indentation error line to identify. To find out the problem run the python command below. The Python command shows the actual issue.

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

There is an another way to identify the indentation error. Open the command prompt in Windows OS or terminal command line window on Linux or Mac, and start the python. The help command shows the error of the python program.

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