Within the standard library, deepcopy is used in about 8 files. list(...) is used in over 100.
If you don't mutate objects that don't belong to you, you'll rarely need deepcopy.
I'm not saying "never use deepcopy" (it certainly CAN be useful), just that every deepcopy call should be questioned.
If you don't mutate objects that don't belong to you, you'll rarely need deepcopy.
I'm not saying "never use deepcopy" (it certainly CAN be useful), just that every deepcopy call should be questioned.
Variables and objects in Python
Unlike many programming languages, variables in Python are not buckets which "contain" objects. In Python, variables are pointers that "point" to objects.
pym.dev
October 22, 2026 at 3:03 PM
Within the standard library, deepcopy is used in about 8 files. list(...) is used in over 100.
If you don't mutate objects that don't belong to you, you'll rarely need deepcopy.
I'm not saying "never use deepcopy" (it certainly CAN be useful), just that every deepcopy call should be questioned.
If you don't mutate objects that don't belong to you, you'll rarely need deepcopy.
I'm not saying "never use deepcopy" (it certainly CAN be useful), just that every deepcopy call should be questioned.
So if you plan to mutate those dictionaries, a shallow copy isn't enough.
You could make a deep copy instead:
from copy import deepcopy
processed_data = deepcopy(tweet_data)
for tweet in processed_data:
tweet["date"] = datetime.strptime(tweet["date"], "%b %d %Y")
You could make a deep copy instead:
from copy import deepcopy
processed_data = deepcopy(tweet_data)
for tweet in processed_data:
tweet["date"] = datetime.strptime(tweet["date"], "%b %d %Y")
October 22, 2026 at 3:03 PM
So if you plan to mutate those dictionaries, a shallow copy isn't enough.
You could make a deep copy instead:
from copy import deepcopy
processed_data = deepcopy(tweet_data)
for tweet in processed_data:
tweet["date"] = datetime.strptime(tweet["date"], "%b %d %Y")
You could make a deep copy instead:
from copy import deepcopy
processed_data = deepcopy(tweet_data)
for tweet in processed_data:
tweet["date"] = datetime.strptime(tweet["date"], "%b %d %Y")
Or we could avoid that deepcopy call by making a new list of new dictionaries instead:
processed_data = [
{**tweet, "date": datetime.strptime(tweet["date"], "%b %d %Y")}
for tweet in tweet_data
]
In Python, we usually prefer making NEW objects over mutating existing ones.
processed_data = [
{**tweet, "date": datetime.strptime(tweet["date"], "%b %d %Y")}
for tweet in tweet_data
]
In Python, we usually prefer making NEW objects over mutating existing ones.
October 22, 2026 at 3:03 PM
Or we could avoid that deepcopy call by making a new list of new dictionaries instead:
processed_data = [
{**tweet, "date": datetime.strptime(tweet["date"], "%b %d %Y")}
for tweet in tweet_data
]
In Python, we usually prefer making NEW objects over mutating existing ones.
processed_data = [
{**tweet, "date": datetime.strptime(tweet["date"], "%b %d %Y")}
for tweet in tweet_data
]
In Python, we usually prefer making NEW objects over mutating existing ones.
Python Tip #295 (of 365):
Avoid needless deep copying. 🧵
Often a deepcopy call can be replaced by a comprehension, a slice, or some other operation that makes new objects.
When you copy a list of dictionaries, you get a NEW list pointing to the SAME dictionaries.
#Python #DailyPythonTip
Avoid needless deep copying. 🧵
Often a deepcopy call can be replaced by a comprehension, a slice, or some other operation that makes new objects.
When you copy a list of dictionaries, you get a NEW list pointing to the SAME dictionaries.
#Python #DailyPythonTip
October 22, 2026 at 3:03 PM
Python Tip #295 (of 365):
Avoid needless deep copying. 🧵
Often a deepcopy call can be replaced by a comprehension, a slice, or some other operation that makes new objects.
When you copy a list of dictionaries, you get a NEW list pointing to the SAME dictionaries.
#Python #DailyPythonTip
Avoid needless deep copying. 🧵
Often a deepcopy call can be replaced by a comprehension, a slice, or some other operation that makes new objects.
When you copy a list of dictionaries, you get a NEW list pointing to the SAME dictionaries.
#Python #DailyPythonTip
An exercise to help build the right mental model for Python data.
- Solution: memory-graph.com#codeurl=http...
- Explanation: github.com/bterwijn/mem...
The Solution link uses 𝗺𝗲𝗺𝗼𝗿𝘆_𝗴𝗿𝗮𝗽𝗵: github.com/bterwijn/mem...
to visualize code execution.
#PythonDev #memory_graph #ShallowCopy #DeepCopy
- Solution: memory-graph.com#codeurl=http...
- Explanation: github.com/bterwijn/mem...
The Solution link uses 𝗺𝗲𝗺𝗼𝗿𝘆_𝗴𝗿𝗮𝗽𝗵: github.com/bterwijn/mem...
to visualize code execution.
#PythonDev #memory_graph #ShallowCopy #DeepCopy
September 16, 2026 at 11:38 PM
An exercise to help build the right mental model for Python data.
- Solution: memory-graph.com#codeurl=http...
- Explanation: github.com/bterwijn/mem...
The Solution link uses 𝗺𝗲𝗺𝗼𝗿𝘆_𝗴𝗿𝗮𝗽𝗵: github.com/bterwijn/mem...
to visualize code execution.
#PythonDev #memory_graph #ShallowCopy #DeepCopy
- Solution: memory-graph.com#codeurl=http...
- Explanation: github.com/bterwijn/mem...
The Solution link uses 𝗺𝗲𝗺𝗼𝗿𝘆_𝗴𝗿𝗮𝗽𝗵: github.com/bterwijn/mem...
to visualize code execution.
#PythonDev #memory_graph #ShallowCopy #DeepCopy
Made with DeepCopy by @charchit.creates
aescripts.com/deepcopy
#aftereffects #aescripts #deepcopy
Stepping back from client work to actually play with mograph again — here’s how this one came together. In-depth tutorials and scripts coming soon, stay tuned 👀
aescripts.com/deepcopy
#aftereffects #aescripts #deepcopy
Stepping back from client work to actually play with mograph again — here’s how this one came together. In-depth tutorials and scripts coming soon, stay tuned 👀
September 11, 2026 at 2:53 AM
Made with DeepCopy by @charchit.creates
aescripts.com/deepcopy
#aftereffects #aescripts #deepcopy
Stepping back from client work to actually play with mograph again — here’s how this one came together. In-depth tutorials and scripts coming soon, stay tuned 👀
aescripts.com/deepcopy
#aftereffects #aescripts #deepcopy
Stepping back from client work to actually play with mograph again — here’s how this one came together. In-depth tutorials and scripts coming soon, stay tuned 👀
🐍 Python Coding Challenge — Day 1229!
Can you predict the output of this Python code without running it? 🤔
This one tests your understanding of Python’s deepcopy() and object identity.
Think carefully and share your answer in the comments! 👇
www.clcoding.com/2026/08/pyth...
Can you predict the output of this Python code without running it? 🤔
This one tests your understanding of Python’s deepcopy() and object identity.
Think carefully and share your answer in the comments! 👇
www.clcoding.com/2026/08/pyth...
August 20, 2026 at 8:15 AM
🐍 Python Coding Challenge — Day 1229!
Can you predict the output of this Python code without running it? 🤔
This one tests your understanding of Python’s deepcopy() and object identity.
Think carefully and share your answer in the comments! 👇
www.clcoding.com/2026/08/pyth...
Can you predict the output of this Python code without running it? 🤔
This one tests your understanding of Python’s deepcopy() and object identity.
Think carefully and share your answer in the comments! 👇
www.clcoding.com/2026/08/pyth...
My DeepCopy package should cross 1 billion downloads in ~ 6 months 💃
github.com/myclabs/Dee...
github.com/myclabs/Dee...
August 11, 2026 at 1:58 PM
My DeepCopy package should cross 1 billion downloads in ~ 6 months 💃
github.com/myclabs/Dee...
github.com/myclabs/Dee...
Made with DeepCopy by @charchit.creates
aescripts.com/deepcopy
#aftereffects #aescripts #deepcopy
Stepping back from client work to actually play with mograph again — here’s how this one came together. In-depth tutorials and scripts coming soon, stay tuned 👀
aescripts.com/deepcopy
#aftereffects #aescripts #deepcopy
Stepping back from client work to actually play with mograph again — here’s how this one came together. In-depth tutorials and scripts coming soon, stay tuned 👀
August 10, 2026 at 6:49 PM
Made with DeepCopy by @charchit.creates
aescripts.com/deepcopy
#aftereffects #aescripts #deepcopy
Stepping back from client work to actually play with mograph again — here’s how this one came together. In-depth tutorials and scripts coming soon, stay tuned 👀
aescripts.com/deepcopy
#aftereffects #aescripts #deepcopy
Stepping back from client work to actually play with mograph again — here’s how this one came together. In-depth tutorials and scripts coming soon, stay tuned 👀
No me digas que una función llamada deepCopy no copia los arrays...
August 27, 2025 at 6:30 PM
No me digas que una función llamada deepCopy no copia los arrays...
Such that it was possible to write functions such as copy and deepCopy that copy all fields from an arbitrary ObjectBase into another ObjectBase, this combined with the annotation processor they wrote allowed them to generate (most) of 5 versions of a web api (soap, another soap api but unmaintained
December 28, 2025 at 11:53 PM
Such that it was possible to write functions such as copy and deepCopy that copy all fields from an arbitrary ObjectBase into another ObjectBase, this combined with the annotation processor they wrote allowed them to generate (most) of 5 versions of a web api (soap, another soap api but unmaintained
jajaja correcto, pero que después del deepcopy se mantenga la referencia es un poco confuso 😅
August 27, 2025 at 7:03 PM
jajaja correcto, pero que después del deepcopy se mantenga la referencia es un poco confuso 😅
Me topé con este caso por primera vez el otro día y reconozco que me costó darme cuenta de lo que estaba pasando. Tiene lógica, pero intuitivo no es, cuando haces deepcopy crees que te estás cubriendo las espaldas...
August 27, 2025 at 5:53 PM
Me topé con este caso por primera vez el otro día y reconozco que me costó darme cuenta de lo que estaba pasando. Tiene lógica, pero intuitivo no es, cuando haces deepcopy crees que te estás cubriendo las espaldas...
The copy module is a built-in module in Python that you can use to copy objects. And in this tutorial, Sara explains how it works. You'll learn about its copy() function, when to use deepcopy(), and how to copy mutable vs immutable objects.
www.freecodecamp.org/news/how-to-...
www.freecodecamp.org/news/how-to-...
July 19, 2025 at 8:01 AM
The copy module is a built-in module in Python that you can use to copy objects. And in this tutorial, Sara explains how it works. You'll learn about its copy() function, when to use deepcopy(), and how to copy mutable vs immutable objects.
www.freecodecamp.org/news/how-to-...
www.freecodecamp.org/news/how-to-...
The copy module is a built-in module in Python that you can use to copy objects. And in this tutorial, Sara explains how it works. You'll learn about its copy() function, when to use deepcopy(), and how to copy mutable vs immutable objects.
www.freecodecamp.org/news/how-to-...
www.freecodecamp.org/news/how-to-...
April 18, 2025 at 8:02 PM
The copy module is a built-in module in Python that you can use to copy objects. And in this tutorial, Sara explains how it works. You'll learn about its copy() function, when to use deepcopy(), and how to copy mutable vs immutable objects.
www.freecodecamp.org/news/how-to-...
www.freecodecamp.org/news/how-to-...
.deepcopy() woes and fixes
Listen to the full episode at realpython.com/podcasts/rpp... or in your preferred podcast client.
Happy Pythoning!
Listen to the full episode at realpython.com/podcasts/rpp... or in your preferred podcast client.
Happy Pythoning!
February 22, 2026 at 2:20 AM
.deepcopy() woes and fixes
Listen to the full episode at realpython.com/podcasts/rpp... or in your preferred podcast client.
Happy Pythoning!
Listen to the full episode at realpython.com/podcasts/rpp... or in your preferred podcast client.
Happy Pythoning!
November 20, 2025 at 1:58 PM
📰🐍 Get the best Python links of the week: PyCoder’s Weekly Issue #709: deepcopy(), JIT, REPL Tricks, and More (Nov. 18, 2025) pycoders.com/issues/709
PyCoder’s Weekly | Issue #709
deepcopy(), JIT, REPL Tricks, and More
pycoders.com
November 18, 2025 at 7:46 PM
📰🐍 Get the best Python links of the week: PyCoder’s Weekly Issue #709: deepcopy(), JIT, REPL Tricks, and More (Nov. 18, 2025) pycoders.com/issues/709
🐝 New Cilium Contributor 🐝
The newest Cilium contributor is @jonathangrahl
They helped preserve ownerreferences when updating ingresses with a shared load balancer 💪
https://github.com/cilium/cilium/pull/28452/
The newest Cilium contributor is @jonathangrahl
They helped preserve ownerreferences when updating ingresses with a shared load balancer 💪
https://github.com/cilium/cilium/pull/28452/
fix: preserve ownerreferences when updating ingresses with a shared load balancer by bittermandel · Pull Request #28452 · cilium/cilium
When the IngressController reconciles a Ingress object which is configured to use a Shared LoadBalancer, each field is copied over from a DeepCopy of the original Ingress and the Status.LoadBalance...
github.com
November 7, 2024 at 9:51 PM
🐝 New Cilium Contributor 🐝
The newest Cilium contributor is @jonathangrahl
They helped preserve ownerreferences when updating ingresses with a shared load balancer 💪
https://github.com/cilium/cilium/pull/28452/
The newest Cilium contributor is @jonathangrahl
They helped preserve ownerreferences when updating ingresses with a shared load balancer 💪
https://github.com/cilium/cilium/pull/28452/
Had a fun bug investigating yesterday where someone was deepcopy()ing a Mock into a service and then being surprised when the mock.method.assert_called_with() wasn't succeeding when clearly a mock with that method was being called with those arguments
July 25, 2024 at 8:39 AM
Had a fun bug investigating yesterday where someone was deepcopy()ing a Mock into a service and then being surprised when the mock.method.assert_called_with() wasn't succeeding when clearly a mock with that method was being called with those arguments
