Block
In Python, code block refers to a collection of code that is in the same block or indent. This is most commonly found in classes, functions, and loops.
You can where code blocks are because they are 1] on the same indent and 2] are uninterrupted by other lines of code not on the same indent.
Python code blocks are useful because they tell you what pieces of code will run as a part of a loop, class, or function.
def code_block[]:
# Everything in this function is part of the same code block
print [1]
print [2]
for i in range[4]:
# Everyting in this loop is part of the same code block
print [i]Let’s take a look at a python to assign a variable code sample.
Python Code Block¶
A code block is a collection of code that sits on the same indent. Think of it like a line of code and it's cousins, brothers, or sisters.
Let's take a look at a few code blocks.
In [1]:
for i in range[4]: print [i]
In [3]:
for i in range[4]: print [i] print [i * 2]
All the code that sits within a function is also a code block
In [6]:
def my_code[]: x = 5 # same block x = x + 4 # same block print [x] # same block my_code[] # Not on the same block of code as above
Check out more Python Vocabulary on our Glossary Page
If statements don't decide on skipping or running the entire code. They only make decisions about a code block.
if True:
print["I'm a code block!"]
We use an indentation of two spaces to highlight code blocks, like how we indented the display statement two spaces to the right.
if True:
print["I'm two spaces away!"]
A code block can be more than a one-liner. All lines with the same indentation belong to the same code block.
We can see it here when we use print[] to add one more line at the beginning.
if True:
print["Look at me!"]
print["I'm a code block"]
It is generally good practice for you not to mix tabs and spaces when coding in Python. Doing this can possibly cause a One of the most distinctive features of Python is its use of indentation to mark blocks of code. Consider the
if-statement from our simple password-checking program: The lines print[‘Logging on …’] and print[‘Incorrect password.’] are two separate code blocks. These ones happen to be only a single line long, but Python lets you write code blocks consisting of any number of statements. To indicate a block of code in Python, you must indent each line of the block by the same amount. The two blocks of code in our example if-statement are both indented four spaces, which is a typical
amount of indentation for Python. In most other programming languages, indentation is used only to help make the code look pretty. But in Python, it is required for indicating what block of code a statement belongs to. For instance, the final print[‘All done!’] is not indented, and so is not part of the else-block. Programmers familiar with other languages often bristle at the thought that indentation matters: Many programmers like the freedom to format their code how they please.
However, Python indentation rules are quite simple, and most programmers already use indentation to make their code readable. Python simply takes this idea one step further and gives meaning to the indentation. An if/elif-statement is a generalized if-statement with more than one condition. It is used for making complex decisions. For example, suppose an airline has the following “child” ticket rates: Kids 2 years old or younger fly for
free, kids older than 2 but younger than 13 pay a discounted child fare, and anyone 13 years or older pays a regular adult fare. The following program determines how much a passenger should pay:TabError, and your program will crash. Be consistent when you code - choose either to indent using tabs or spaces and follow your chosen convention throughout your program.Code Blocks and Indentation
if pwd == 'apple':
print['Logging on ...']
else:
print['Incorrect password.']
print['All done!']If/elif-statements
# airfare.py
age = int[input['How old are you? ']]
if age