Python CSV文件查询：开发根据城市获取对应文件完整路径的交互式代码

Hey there! Let's build a simple interactive Python script that does exactly what you need—letting users input a city name and getting the full path to the corresponding CSV file. Here's a step-by-step solution:

How it works #

We'll create a script that:

1. Stores the mapping between city names and their CSV filenames (or dynamically generates filenames if they follow a strict pattern)
2. Takes user input for the city
3. Validates the input and returns the full file path (with error handling for invalid cities or missing files)

Full Code Example #

import os

def retrieve_city_csv_path():
    # Update this to the actual directory where your CSV files are stored
    csv_directory = "/your/actual/csv/directory/path"
    
    # Map city names to their corresponding CSV filenames
    # Replace these with your actual city names and file names
    city_to_csv = {
        "Beijing": "beijing_data.csv",
        "Shanghai": "shanghai_metrics.csv",
        "Guangzhou": "guangzhou_stats.csv"
    }
    
    # Get user input with cleanup to avoid accidental spaces
    user_city = input("Please enter the city name to look up: ").strip()
    
    # Check if the city is supported
    if user_city in city_to_csv:
        # Build the full path safely (works across Windows/macOS/Linux)
        full_file_path = os.path.join(csv_directory, city_to_csv[user_city])
        
        # Optional: Verify the file actually exists for robustness
        if os.path.isfile(full_file_path):
            print(f"✅ Full path to the CSV file: {full_file_path}")
            return full_file_path
        else:
            print(f"❌ Error: File not found at {full_file_path}. Please check the file exists.")
    else:
        supported_cities = ", ".join(city_to_csv.keys())
        print(f"❌ Error: '{user_city}' is not a supported city. Supported cities are: {supported_cities}")

# Run the interactive function
if __name__ == "__main__":
    retrieve_city_csv_path()

Key Customization Points #

• CSV Directory: Change csv_directory to the real folder where your CSV files live. Using os.path.join ensures the path works seamlessly across different operating systems.
• City-to-File Mapping: Update city_to_csv with your three cities and their exact CSV filenames. If your CSVs are named exactly like the city (e.g., "Chengdu.csv" for Chengdu), you can simplify this to a list and generate the filename dynamically:

  supported_cities = ["Chengdu", "Shenzhen", "Hangzhou"]
  if user_city in supported_cities:
      full_file_path = os.path.join(csv_directory, f"{user_city}.csv")
  

• Error Handling: The script checks for both invalid city names and missing files, which makes it more reliable for real-world use cases.

Quick Tips #

• If you plan to add more cities later, just update the mapping/list—no need to rewrite the core logic.
• For larger projects, you could store the city list and CSV directory in a config file (like config.json) to keep your code clean and easy to maintain.

内容的提问来源于stack exchange，提问作者python_newbie