我一直在關注本教程：https : //kb.objectrocket.com/postgresql/scrape-a-website-to-postgres-with-python-938
我的app.py檔案看起來像這樣（取自上述教程）：
from flask import Flask # needed for flask-dependent libraries below
from flask import render_template # to render the error page
from selenium import webdriver # to grab source from URL
from bs4 import BeautifulSoup # for searching through HTML
import psycopg2 # for database access
# set up Postgres database connection and cursor.
t_host = "localhost" # either "localhost", a domain name, or an IP address.
t_port = "5432" # default postgres port
t_dbname = "scrape"
t_user = "postgres"
t_pw = "********"
db_conn = psycopg2.connect(host=t_host, port=t_port, dbname=t_dbname, user=t_user, password=t_pw)
db_cursor = db_conn.cursor()
app = Flask(__name__)
@app.route('/import_temp')
def import_temp():
# set up your webdriver to use Chrome web browser
my_web_driver = webdriver.Chrome("/usr/lib/chromium-browser/chromedriver")
# designate the URL we want to scrape
# NOTE: the long string of characters at the end of this URL below is a clue that
# maybe this page is so dynamic, like maybe refers to a specific web session and/or day/time,
# that we can't necessarily count on it to be the same more than one time.
# Which means... we may want to find another source for our data; one that is more
# dependable. That said, whatever URL you use, the methodology in this lesson stands.
t_url = "https://weather.com/weather/today/l/7ebb344012f0c5ff88820d763da89ed94306a86c770fda50c983bf01a0f55c0d"
# initiate scrape of website page data
my_web_driver.get("<a href='" t_url "'>" t_url "</a>")
# return entire page into "t_content"
t_content = my_web_driver.page_source
# use soup to make page content easily searchable
soup_in_bowl = BeautifulSoup(t_content)
# search for the UNIQUE span and class for the data we are looking for:
o_temp = soup_in_bowl.find('span', attrs={'class': 'deg-feels'})
# from the resulting object, "o_temp", get the text parameter and assign it to "n_temp"
n_temp = o_temp.text
# Build SQL for purpose of:
# saving the temperature data to a new row
s = ""
s = "INSERT INTO tbl_temperatures"
s = "("
s = "n_temp"
s = ") VALUES ("
s = "(%n_temp)"
s = ")"
# Trap errors for opening the file
try:
db_cursor.execute(s, [n_temp, n_temp])
db_conn.commit()
except psycopg2.Error as e:
t_msg = "Database error: " e "/n open() SQL: " s
return render_template("error_page.html", t_msg = t_msg)
# Success!
# Show a message to user.
t_msg = "Successful scrape!"
return render_template("progress.html", t_msg = t_msg)
# Clean up the cursor and connection objects
db_cursor.close()
db_conn.close()
當我運行代碼并轉到http://127.0.0.1:5000 時，我收到了 404 錯誤訊息：
Not Found
The requested URL was not found on the server. If you entered the URL manually please check your spelling and try again.
這是命令列的輸出：
FLASK_APP = app.py
FLASK_ENV = development
FLASK_DEBUG = 0
In folder /home/lloyd/PycharmProjects/flaskProject
/home/lloyd/PycharmProjects/flaskProject/venv/bin/python -m flask run
* Serving Flask app 'app.py' (lazy loading)
* Environment: development
* Debug mode: off
* Running on http://127.0.0.1:5000/ (Press CTRL C to quit)
127.0.0.1 - - [28/Dec/2021 08:25:01] "GET / HTTP/1.1" 404 -
我確實運行了一個成功的測驗“Hello World”專案。
任何有關為什么我收到此錯誤的見解將不勝感激。
勞埃德
uj5u.com熱心網友回復：
我認為您還沒有看到您在問題中鏈接的整個教程。它顯然使用將兩條路線指向一起作為一種方法。
@app.route("/") # I think you have missed this.
# Set up Postgres database connection and cursor.
t_host = "PostgreSQL database host address" # either "localhost", a domain name, or an IP address.
t_port = "5432" # default postgres port
t_dbname = "database name"
t_user = "database user name"
t_pw = "password"
db_conn = psycopg2.connect(host=t_host, port=t_port, dbname=t_dbname, user=t_user, password=t_pw)
db_cursor = db_conn.cursor()
@app.route("/import_temp")
def import_temp():
另外，請注意這可以組合在一起。
@app.route("/")
@app.route("/import_temp")
def import_temp():
# Do something
uj5u.com熱心網友回復：
首先打開終端然后輸入“ pip install flask ”，完成后按回車然后輸入“ import flask ”然后按回車。這將解決您的問題。
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