update script with input validation, error handling, data visual and readme

Author: aafaris

Real-Time Cryptocurrency Price Tracker/Readme.md

@@ -0,0 +1,29 @@
+# Cryptocurrency Price Tracker with CoinGecko API
+
+## Project Overview
+
+The **Real-Time Cryptocurrency Price Tracker** is a Python script that allows users to retrieve real-time cryptocurrency prices, percentage price changes, and historical price data using the CoinGecko public API. The script also offers a simple visualization of historical price trends. Refer to [CoinGecko API](https://docs.coingecko.com/v3.0.1/reference/introduction) and [CoinGecko Coins List](https://api.coingecko.com/api/v3/coins/list) for more information.
+
+## Features
+
+- **Real-Time Price Retrieval**: Input the name of a cryptocurrency (eg. bitcoin) to retrieve its current price in USD
+- **24-Hour Price Change**: Displays the 24-hour percentage change in price for the selected cryptocurrency
+- **Historical Price Data**: Retrieve historical price data for a specified number of days (eg. 1 day, 7 days, or 30 days) and visualize it in a chart
+- **Data Visualization**: Uses matplotlib to generate a line chart displaying the historical price data
+
+
+## Technologies Used
+
+- **Python**: The core programming language used to build the script
+- **CoinGecko API**: A free API used to fetch cryptocurrency prices, percentage changes, and historical data
+- **Requests**: A Python library for making HTTP requests to the CoinGecko API
+- **Matplotlib**: A Python library used to visualize historical cryptocurrency price data in a line chart format
+- **Datetime**: Python datetime module is used to convert and handle timestamps when retrieving historical price data
+
+## Prerequisites
+
+Before running the application, ensure you have the following:
+
+- [Python 3.x](https://www.python.org/downloads/) installed on your system
+- `requests` and `matplotlib` libraries are installed. Refer to `requirements.txt` for a specific version
+  

Real-Time Cryptocurrency Price Tracker/main.py

@@ -1,4 +1,6 @@
 import requests
+import matplotlib.pyplot as plt
+import datetime
 
 COINGECKO_API_URL = "https://api.coingecko.com/api/v3"
 
@@ -13,42 +15,80 @@ def get_crypto_price(crypto_symbol):
 
     if response.status_code == 200:
         data = response.json()
-        price = data[crypto_symbol]['usd']
-        change_percentage = data[crypto_symbol]['usd_24h_change']
-        return price, change_percentage
+        if crypto_symbol in data:
+            price = data[crypto_symbol]['usd']
+            change_percentage = data[crypto_symbol]['usd_24h_change']
+            return price, change_percentage
+        else:
+            raise ValueError(f"Cryptocurrency '{crypto_symbol}' not found.")
     else:
-        return None
+        raise Exception(f"Failed to fetch data: {response.status_code} - {response.reason}")
 
 
 def get_historical_data(crypto_symbol, days):
     response = requests.get(f"{COINGECKO_API_URL}/coins/{crypto_symbol}/market_chart", params={
         'vs_currency': 'usd',
         'days': days
     })
+
     if response.status_code == 200:
-        return response.json()['prices']  # Returns price data over the days
+        data = response.json()
+        if 'prices' in data:
+            return data['prices']  # Returns price data over the days
+        else:
+            raise ValueError(f"No historical data available for '{crypto_symbol}'.")
     else:
-        return None
+        raise Exception(f"Failed to fetch historical data: {response.status_code} - {response.reason}")
+
+
+def plot_historical_data(historical_data, crypto_symbol):
+    dates = [datetime.datetime.fromtimestamp(item[0] / 1000) for item in historical_data]
+    prices = [item[1] for item in historical_data]
+
+    plt.figure(figsize=(10, 6))
+    plt.plot(dates, prices, marker='o', linestyle='-', color='b')
+    plt.title(f'Historical Price Data for {crypto_symbol.capitalize()}')
+    plt.xlabel('Date')
+    plt.ylabel('Price (USD)')
+    plt.xticks(rotation=45)
+    plt.grid(True)
+    plt.tight_layout()
+    plt.show()
 
 
 def main():
-    print("You may refer to https://api.coingecko.com/api/v3/coins/list for the coins list")
-    crypto = input("Enter cryptocurrency symbol (e.g. bitcoin, ethereum): ").lower()
-    price, change = get_crypto_price(crypto)
+    crypto = input("Enter cryptocurrency symbol (eg. bitcoin, ethereum): ").lower()
 
-    if price:
+    try:
+        # Get real-time price and 24-hour change
+        price, change = get_crypto_price(crypto)
         print(f"Current price of {crypto}: ${price}")
         print(f"24-hour change: {change:.2f}%")
+    except ValueError as e:
+        print(f"Error: {e}")
+        return
+    except Exception as e:
+        print(f"Error fetching price data: {e}")
+        return
+
+    # Validate and get historical data
+    while True:
+        try:
+            days = int(input("Enter the number of days for historical data (eg. 1, 7, 30): "))
+            if days <= 0:
+                raise ValueError("The number of days must be a positive integer.")
+            break
+        except ValueError as e:
+            print(f"Invalid input: {e}. Please enter a valid number.")
 
-        # Get historical data
-        days = input("Enter the number of days for historical data: ")
+    try:
         historical_data = get_historical_data(crypto, days)
-        if historical_data:
-            print(historical_data)
-            print("Historical data retrieved successfully.")
-            # You may process historical_data further (e.g., plot or analyze it)
-    else:
-        print("Invalid cryptocurrency symbol or failed API request.")
+        print("Historical data retrieved successfully.")
+        plot_historical_data(historical_data, crypto)
+    except ValueError as e:
+        print(f"Error: {e}")
+    except Exception as e:
+        print(f"Error fetching historical data: {e}")
 
 
 if __name__ == "__main__":

Real-Time Cryptocurrency Price Tracker/requirements.txt

@@ -1 +1,2 @@
-requests==2.32.3
+requests==2.32.3
+matplotlib==3.9.2