That creates a list of one element with just the node object. Presumably results is expected to be a list.
Reddit
reddit.com › r/learnpython › question regarding using square brackets to access values of variables
r/learnpython on Reddit: Question regarding using square brackets to access values of variables
February 4, 2025 -
Hello,
Please review the code in bold.
My question is in both examples,
Example 1.
python_topics = ["variables", "control flow", "loops", "modules", "classes"]
length = len(python_topics)
index = 0
while index < length:
print("I am learning about " + python_topics[index])
index += 1
Example 2.
favorite_fruit = "blueberry"
last_char = favorite_fruit**[len(favorite_fruit) - 1]**
Output: Y
My question is, their a way to describe what the square brackets are doing? Would you say that the square brackets are used to access or transfer the value of the variable? Hopefully this question makes sense. Thank you very much.
Top answer 1 of 5
8
You are accessing a reference at some index. Or, in the case of dictionaries, some key. This holds true regardless of how you're actually making use of it. However, as a general case it could technically do nearly anything, as it's simply calling the object's __getitem__-method under the hood. The above example print("I am learning about " + python_topics[index]) could therefore be technically written as print("I am learning about " + python_topics.__getitem__(index)) although, of course, no sane person would outside of an example case like this one.
2 of 5
5
Would you say that the square brackets are used to access or transfer the value of the variable? Access. "Transfer" implies that the data is moving out of the sequence (e.g. list.pop), which is not the case here.
Tuple declaration using square brackets
VAR = Tuple[…] I was expecting Tuple with parentheses. Any help to understand · The “Tuple” is a type very similar to standard “tuple”, but this one is imported from typing and I am not able to understand it, as you can see below syntax: · This looks like a type docstring (documentation ... More on discuss.python.org
0
0
July 21, 2022python - What do the square brackets around parameters mean in the official documentation? - Stack Overflow
The short version: If a parameter is enclosed in square brackets, it is optional. More on stackoverflow.com
Meaning of square brackets
Ok, I think I have got it now. it is about the indexing of a list. I think it is referring to the last two elements of the list called mails · The first thing to understand is that the output from split() is a list. See the documentation for str.split(). A list is a sequence type · The second ... More on discuss.python.org
0
0
October 24, 2022double square brackets side by side in python - Stack Overflow
The professor has asked that we ... in Python for something that will be 'similar'. I managed to find several ways to code it but I found several people using some code that I don't understand. Essentially, I'm looking to find out what it means (or does) when you see a list or variable that has two square brackets side by ... More on stackoverflow.com
Videos
Data Science Discovery
discovery.cs.illinois.edu › guides › Python-Fundamentals › brackets
Parentheses, Square Brackets and Curly Braces in Python - Data Science Discovery
March 22, 2024 - Brief description on when to use parentheses `()`, square brackets `[]` and curly braces `{}` in python
Python.org
discuss.python.org › python help
Tuple declaration using square brackets - Python Help - Discussions on Python.org
July 21, 2022 - I sometimes see this Tuple declaration which is not common: VARIABLE = Tuple[List[Tuple[str, float, Dict[str, Any]]], Dict[str, str]] VAR = Tuple[…] I was expecting Tuple with parentheses. Any help to understand? Tha…
SheCodes
shecodes.io › athena › 2453-how-to-use-square-bracket-syntax-in-python
[Python] - How to Use Square Bracket Syntax in Python - | SheCodes
Learn what square bracket syntax is and how to use it to access elements of an array or dictionary in Python.
GeeksforGeeks
geeksforgeeks.org › python › parentheses-square-brackets-and-curly-braces-in-python
Parentheses, Square Brackets and Curly Braces in Python - GeeksforGeeks
July 26, 2025 - Curly braces define dictionaries and sets, both of which are mutable collections. Square brackets are crucial for defining lists and accessing elements through indexing and slicing.
Medium
medium.com › generative-design › fundamentals-of-python-variables-b0523dd698a7
Fundamentals of Python — Variables | by Danil Nagy | Generative Design | Medium
February 5, 2017 - To retrieve an object from such a list, you once again use square brackets, but this time appended to the end of the variable name. Inside the brackets you place the index or place of the piece of data you want.
Afeld
python-public-policy.afeld.me › en › columbia › brackets.html
Brackets in Python and pandas — Python for Public Policy @ Columbia University
To do so, we pass a dictionary ... [3, 4, 5], "col3": [6.32, 8.1, 4.9], } ) df · To retrieve a single column, take the DataFrame variable followed by square brackets, passing in the name (label) of a column as a string....
Edlitera
edlitera.com › blog › posts › python-parentheses
Python Parentheses Cheat Sheet | Edlitera
The standard formulation when using square brackets to retrieve a slice of data is [start:end:step]. The step part is often omitted when wanting to retrieve a whole subset of a collection. When skipped, the step variable defaults to one.
Quora
quora.com › What-is-the-use-of-square-brackets-in-Python-except-list
What is the use of square brackets in Python, except list? - Quora
Answer (1 of 4): [] apart from being used to represent an empty list can also be used in the following ways: array indexing: [code]a = [1, 2, 3, 4, 5] # access first element print(a[0]) # access last element print(a[-1]) [/code]dictionary indexing: ...
Squash
squash.io › accessing-python-data-structures-dynamically-with-square-brackets
How to Access Python Data Structures with Square Brackets
October 14, 2023 - Python allows you to use variables inside square brackets to dynamically access elements in data structures.
YouTube
youtube.com › watch
How to Use Square Brackets in Python - YouTube
Using Python parentheses correctly is important to avoid syntax errors. We continue our three-part Python Parentheses series with square brackets. Square bra...
Published March 7, 2023
Reuven Lerner
lerner.co.il › home › blog › python › python parentheses primer
Python parentheses primer — Reuven Lerner
November 10, 2022 - The square brackets tell Python that this is a list comprehension, producing a list.
Python.org
discuss.python.org › python help
Meaning of square brackets - Python Help - Discussions on Python.org
October 24, 2022 - Ok, I think I have got it now. it is about the indexing of a list. I think it is referring to the last two elements of the list called mails · The first thing to understand is that the output from split() is a list. See the documentation for str.split(). A list is a sequence type · The second ...
Coderanch
coderanch.com › t › 737170 › languages › square-brackets-print-line
What are the square brackets around the print line used for? (Jython/Python forum at Coderanch)
November 30, 2020 - In a lot of languages, there exists a standard syntax for declaring (and displaying) complex objects. The "[]" bracket an array or list (sequential collection) The "{}" bracket a dictionary entry or object with properties: {name: value} or {name, v1= value1, v2=value2, …} The exact format ...
Runestone Academy
runestone.academy › ns › books › published › fopp › Sequences › IndexOperatorWorkingwiththeCharactersofaString.html
6.3. Index Operator: Working with the Characters of a String — Foundations of Python Programming
The indexing operator (Python uses square brackets to enclose the index) selects a single character from a string. The characters are accessed by their position or index value.
Top answer 1 of 2
26
If you have a list
l = ["foo", "bar", "buz"]
Then l[0] is "foo", l[1] is "bar", l[2] is buz.
Similarly you could have a list in it instead of strings.
l = [ [1,2,3], "bar", "buz"]
Now l[0] is [1,2,3].
What if you want to access the second item in that list of numbers? You could say:
l[0][1]
l[0] first gets you the list, then [1] picks out the second number in it. That's why you have "square bracket next to square bracket".
2 of 2
9
Square brackets are used to define lists, but also to get things from lists.
When you have a list of lists and want something from an inner list, you need to get that inner list (using brackets) and then get the desired thing inside (using brackets again).
lol = [[1, 2, 3], [4, 5, 6]]
lol[1]
# [4, 5, 6]
lol[1][0]
# 4
Top answer 1 of 2
2
Variable points to a nested list, where length of outer as well as inner list is 1.
In [9]: lst = [[1]]
In [10]: len(lst)
Out[10]: 1
In [11]: len(lst[0])
Out[11]: 1
Appending list to an empty list,
In [12]: lst = []
In [13]: lst.append([1])
In [14]: lst
Out[14]: [[1]]
2 of 2
0
It depends on what data type some_var is holding. If some_var is a primitive data type, say integer, then lst is a list of list of an integer. But if some_var is a list itself, then lst is a list of list of list
Processing
py.processing.org › reference › indexbrackets.html
[] (Index brackets) \ Language (API)
Python Mode for Processing extends the Processing Development Environment with the Python programming language.