如果需要使用者傳遞檔案，要先建個資料夾在專案根目錄使用 POST 上傳，檔案就會傳到剛剛建好的資料夾裡
輸入參數選 Body -> form-data ， 檔案先放在 C:/Users/<user name>/Postman/files裡面；KEY 格式選 File， VALUE 選擇檔案後按 Send
app.py

import os
from flask import Flask, request
from werkzeug.utils import secure_filename


app = Flask(__name__)
app.config["DEBUG"] = True
app.config["ALLOW_EXTENSIONS"] = ['jpg']


def is_allow_extensions(filename): # 判斷副檔名是否允許上傳
    return ('.' in filename) and (filename.split('.')[-1].lower() in app.config['ALLOW_EXTENSIONS'])


@app.route("/", methods=["POST"])
def file_upload():
    f = request.files["files"]
    filename = secure_filename(f.filename)
    if is_allow_extensions(filename):
        f.save(os.path.join(app.config['UPLOAD_FOLDER'], filename))
        return 'success'
    else:
        return 'error'
        
        
if __name__ == "__main__":
    app.run()

執行結果