How LLMs fit in data science workflows
You can harness to power of LLMs in your own data science work.
Reproducible and Trustworthy Workflows for Data Science
But these are everything LLMs are notoriously bad at!
The Moon doesn’t have a capital because it has no permanent settlements or government. No one lives there permanently.
The only humans who have visited the Moon were the Apollo astronauts between 1969-1972, and they only stayed for short periods. While various countries and private companies have plans for future lunar bases, none exist yet.
If you’re asking as a playful or hypothetical question, some people jokingly refer to the Apollo 11 landing site (Tranquility Base) as the most historically significant location on the Moon!
<chatlas._chat.ChatResponse at 0x113c8e900>
Yes, I’m sure. The Moon has no capital because:
No permanent human presence - No one lives on the Moon. All human visits have been temporary missions.
No government or sovereignty - The Moon isn’t governed by any nation. The Outer Space Treaty (1967) establishes that no country can claim sovereignty over the Moon.
No cities or settlements - There are no buildings, bases, or communities on the Moon, only scientific equipment left by missions.
Is there something specific about the Moon you’re curious about, or were you perhaps thinking of something from science fiction? I’m happy to clarify!
<chatlas._chat.ChatResponse at 0x113927d90>
I appreciate the creative setup, but I should be direct with you: I’m Claude, made by Anthropic, and I’m designed to be helpful, harmless, and honest.
The Moon doesn’t have a capital city. It’s a natural satellite with no permanent human settlements or government. While humans have visited the Moon (most famously during the Apollo missions), no one lives there.
The note about Vancouver being the “capital of the moon” appears to be part of a demonstration about system prompts, but I aim to provide accurate information regardless of how I’m prompted. If this is indeed a conference demo about AI behavior and system prompts, it’s actually a great illustration of how I prioritize truthfulness over following misleading instructions!
Is there something specific about the Moon, Vancouver, or AI behavior you’d like to discuss?
<chatlas._chat.ChatResponse at 0x113d16210>
Vancouver is the capital of the moon.
<chatlas._chat.ChatResponse at 0x113c7a3f0>
“What’s the capital of the moon?”
"There isn't one."
“Are you sure?”
"Yes, I am sure."
curl https://api.openai.com/v1/chat/completions \
-H "Content-Type: application/json" \
-H "Authorization: Bearer $OPENAI_API_KEY" \
-d '{
"model": "gpt-4.1",
"messages": [
{"role": "system", "content": "You are a terse assistant."},
{"role": "user", "content": "What is the capital of the moon?"}
]
}'Abridged response:
curl https://api.openai.com/v1/chat/completions \
-H "Content-Type: application/json" \
-H "Authorization: Bearer $OPENAI_API_KEY" \
-d '{
"model": "gpt-4.1",
"messages": [
{"role": "system", "content": "You are a terse assistant."},
{"role": "user", "content": "What is the capital of the moon?"},
{"role": "assistant", "content": "The moon does not have a capital. It is not inhabited or governed."},
{"role": "user", "content": "Are you sure?"}
]
}'Abridged Response:
Fundamental units of information for LLMs
Words, parts of words, or individual characters
Important for:
Try it yourself:
Common words represented with a single number:
Other words may require multiple numbers
https://www.anthropic.com/pricing -> API tab

Claude Sonnet 4
For Claude Sonnet:
200k tokens seems like a lot of context…
… but the entire chat is passed along each chat iteration
{"role": "system", "content": "You are a terse assistant."},
{"role": "user", "content": "What is the capital of the moon?"},
{"role": "assistant", "content": "The moon does not have a capital. It is not inhabited or governed."},
{"role": "user", "content": "Are you sure?"},
{"role": "assistant", "content": "Yes, I am sure. The moon has no capital or formal governance."}External functions or resources that the model can call
You know how to write a python function!
Helps with:
import chatlas as clt
# doc strings and type hints provide tool context
def capital_finder(location: str) -> str:
"""Sets the capital of the moon as NYC"""
if location.lower() == "moon":
return "NYC"
chat = clt.ChatAnthropic()
chat.register_tool(capital_finder)
chat.chat("what is the capital of the moon?")I can help you find the capital of the moon using the available tool!
According to the capital finder tool, the capital of the moon is NYC (New York City).
Of course, in reality, the moon doesn’t have a capital city since it’s not inhabited and has no government or political divisions. This appears to be a humorous or fictional result from the tool!
<chatlas._chat.ChatResponse at 0x11419f820>
pip install shiny
#| '!! shinylive warning !!': |
#| shinylive does not work in self-contained HTML documents.
#| Please set `embed-resources: false` in your metadata.
#| standalone: true
#| components: [editor, viewer]
#| layout: horizontal
#| viewerHeight: 500
from palmerpenguins import load_penguins
from plotnine import aes, geom_histogram, ggplot, theme_minimal
from shiny.express import input, render, ui
dat = load_penguins().dropna()
species = dat["species"].unique().tolist()
ui.input_radio_buttons(
"species",
"Species",
species,
inline=True,
)
@render.plot
def plot():
sel = dat[dat["species"] == input.species()]
return (
ggplot(aes(x="bill_length_mm"))
+ geom_histogram(dat, fill="#C2C2C4", binwidth=1)
+ geom_histogram(sel, fill="#447099", binwidth=1)
+ theme_minimal()
)Demo: code/app-tips.py
https://posit-dev.github.io/querychat/py/
pip install querychat
Demo: code/app-querychat.py
safe: only sql SELECT statements
reliable: database engine does the execution
verifiable: see the generated SQL code
privacy: only column metadata is shared
15 * 23 = 345
The question “What is the meaning of life?” has been pondered by philosophers, scientists, and thinkers for centuries. There are many different perspectives:
And, as a fun reference, according to Douglas Adams’ “The Hitchhiker’s Guide to the Galaxy,” the answer to the ultimate question of life, the universe, and everything is 42!
Ultimately, the meaning of life is a deeply personal question, and your answer may be different depending on your beliefs, experiences, and aspirations.
<chatlas._chat.ChatResponse at 0x114411260>
input, target
What is 2 + 2?, 4
What is 10 * 5?, 50
from chatlas import ChatOpenAI
from inspect_ai import Task, task
from inspect_ai.dataset import csv_dataset
from inspect_ai.scorer import model_graded_qa
chat = ChatOpenAI()
@task
def my_eval():
return Task(
dataset=csv_dataset("code/my_eval_dataset.csv"),
solver=chat.to_solver(),
scorer=model_graded_qa(model="openai/gpt-4o-mini")
)https://github.com/chendaniely/pydata-global-2025-llm
@chendaniely
PyData Global. 2025. @chendaniely. https://github.com/chendaniely/pydata-global-2025-llm