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Streamlit makes it remarkably fast to transform raw Python scripts into interactive, web-based data applications without needing any frontend knowledge in HTML, CSS, or JavaScript. In this tutorial, we will build a full-featured **Sales Analytics Dashboard** complete with real-time sidebar filtering, custom KPI metric cards, dynamic line/bar charts, and expandable data preview tables. --- ## Prerequisites To follow along, make sure you have Python 3.9+ installed along with the required libraries: bash pip install streamlit pandas numpy --- ## Step 1: Setting Up the Page & Mock Data with Caching First, we import the necessary libraries, set up the layout, and create a function to generate mock sales records. We use Streamlit’s `@st.cache_data` decorator so the data is only generated once per session, keeping the app snappy during user interactions. python import streamlit as st import pandas as pd import numpy as np Set layout configuration st.set_page_config(page_title="Sales Dashboard", layout="wide") Cache data loading for performance optimization @st .cache_data def load_data(): dates = pd.date_range("2025-01-01", periods=180) regions = ["North", "South", "East", "West"] df = pd.DataFrame({ "date": np.random.choice(dates, 500), "region": np.random.choice(regions, 500), "product": np.random.choice(["A", "B", "C"], 500), "sales": np.random.randint(100, 5000, 500), "units": np.random.randint(1, 50, 500), }) return df.sort_values("date") df = load_data() --- ## Step 2: Adding Interactive Sidebar Filters Next, we add controls inside the sidebar to let users filter the dataset by region, product type, and date range. A boolean mask applies those selections dynamically. python --- Sidebar filters --- st.sidebar.header("Filters") region_filter = st.sidebar.multiselect("Region", df["region"].unique(), default=df["region"].unique()) product_filter = st.sidebar.multiselect("Product", df["product"].unique(), default=df["product"].unique()) date_range = st.sidebar.date_input(

LSTMs are still the go-to architecture for a lot of time series work, but they're annoying to trust. You get a number out the other end and no real sense of why the model landed there. This tutorial walks through training an LSTM on daily temperature data, then pulling it apart with three explainability methods: permutation importance, SHAP, and Integrated Gradients. Who this is for: people who already know some Keras and want to add interpretability to a forecasting model, not a from-scratch intro to neural nets. 1. Getting the data into shape LSTMs want a 3D tensor — (samples, timesteps, features) — so before anything else we need to turn a flat column of temperatures into overlapping 7-day windows, each one paired with the value on day 8. import numpy as np import pandas as pd from sklearn.preprocessing import MinMaxScaler # 1. Load data df = pd . read_csv ( " weather_data.csv " ) data = df [ ' Temperature ' ]. values . reshape ( - 1 , 1 ) # 2. Scale the data for stable neural network training scaler = MinMaxScaler ( feature_range = ( 0 , 1 )) scaled_data = scaler . fit_transform ( data ) # 3. Create sequences: 7 days of lag to predict the 8th day X , y = [], [] for i in range ( 7 , len ( scaled_data )): X . append ( scaled_data [ i - 7 : i ]) y . append ( scaled_data [ i ]) X , y = np . array ( X ), np . array ( y ) print ( f " Input shape: { X . shape } " ) # Output: (Samples, 7, 1) Scaling matters more than it sounds like it should — LSTMs trained on unscaled temperature values are prone to exploding gradients, and training just falls apart. The windowing step is really the whole trick here: every prediction only ever sees the past seven days, nothing more. 2. Building the model Two stacked LSTM layers, dropout after each one, early stopping so we don't have to babysit the epoch count. from tensorflow.keras.models import Sequential from tensorflow.keras.layers import LSTM , Dense , Dropout , Input from tensorflow.keras.callbacks import EarlyStopping # 1. Build

Flames burned through the Deep Space Communications Complex near Madrid, but NASA has been unable to assess the damage as a wildfire emergency grips the region.

This climate phenomenon could cause a massive global temperature spike and cause economic losses of $10 trillion by 2032.

Google's AlphaFold can help ID what parts of a gene editing protein enable mistakes.

"These are things that tend to be really hard."

The Trump administration unveiled the first "Genesis Mission" grants on Thursday, directing $5 billion toward hundreds of AI-driven science projects in an effort the White House has described as "comparable in urgency and ambition to the Manhattan Project." At roughly the same time, Trump's science adviser Michael Kratsios was on Capitol Hill selling lawmakers on […]

Relativity Space announced plans to build a second rocket factory near Cape Canaveral, Florida.

Never mind the “heat death of the universe.” Entropy is just a bridge between two levels of reality.

Outside experts—some with a vested interest in peptides—recommended adding a number of the amino acids to the FDA's bulk list, including the “Wolverine stack” touted by Joe Rogan and other influencers.

The breathalyzer identifies the amount of acetone in your breath to determine if your body is in ketosis.

The resulting report is a near-random mixture of real problems and grievances.

The EPA has proposed a rule change that would let states decide how much input the public has on air pollution permits. It would be a huge boon for data centers increasingly reliant on fossil fuels.

Hear from six pediatricians in measles hot spot Utah, as the US faces infection levels not seen in over three decades and prepares to lose its status as a country that eliminated the dangerous disease.

“We think this may help younger orcas feed more easily, or it could also just be for fun.”

Best-of-K eval selection bias: pick the highest-scoring config from K candidates on one eval set and that observed score is biased up. It reports the expected maximum of K noisy estimates, which beats the field mean whenever K exceeds one. The bias appears even when all K configs are truly equal, grows with K, and shrinks with n. Here is the version that bites you. Your bake-off ran a batch of prompts against one eval set, the top one came out ahead, and you shipped it. In production it does worse. That drop reads like bad luck, or drift, or a bad week. It is none of those. It is a number you could have computed before you shipped, and it gets larger the more candidates you tried. I ran a small script to make the gap concrete. Eight configs, one hundred eval items, and here is the catch: I made all eight configs truly identical , every one a fair coin at 50%. There is no real best. Nothing to tune. Then I let selection pick a winner anyway: config 0: 47/100 = 47.0% config 1: 50/100 = 50.0% config 2: 52/100 = 52.0% config 3: 52/100 = 52.0% config 4: 50/100 = 50.0% config 5: 50/100 = 50.0% config 6: 54/100 = 54.0% <- selected winner (argmax) config 7: 44/100 = 44.0% config 6: 54.0% (k=54 n=100 SE=4.98) config 2: 52.0% (k=52 n=100 SE=5.00) RANK: INDISTINGUISHABLE - gap 2.00 pp against 7.06 pooled SE = 0.28 SE < 2.0. Ranking "config 6" above "config 2" is NOT allowed. Held-out the winner on a fresh 100 items: 48/100 = 48.0%. Config 6 wins the bake-off at 54.0%. Then I asked the same eval-guard I use in the McNemar and rule-of-three pieces to rank config 6 against the runner-up. It refused: the gap is 0.28 SE, far under the two-SE bar, so INDISTINGUISHABLE . The ranker would not call config 6 the best. Selection did. And on a fresh held-out set the 54.0% falls back to 48.0%, toward the true 50% it was always going to be. TL;DR Picking the best of K configs by observed pass rate reports the expected maximum of K noisy estimates. The max of K exceeds the field mean, strict

The cyclospora diarrhea outbreak isn't an isolated incident. It's part of a pattern of leafy greens wreaking digestive havoc.

Several federal agencies are contributing toward the interdisciplinary research efforts.

A mirror that moves mid-photon could release a shower of new photons.

In the face of backlash to concerns the AI boom will increase consumer electricity bills, the largest utility companies and data center developers in the US are now promising to do something about it. The Wall Street Journal reports that nearly 200 organizations have signed President Donald Trump's "rate payer protection pledge" that's meant to […]