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in Python by (150 points)
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import requests
from bs4 import BeautifulSoup

page = requests.get('https://forecast.weather.gov/MapClick.php?lat=45.2541&lon=-113.2262#.Xn8kMIgzZPY')
soup = BeautifulSoup(page.content, 'html.parser')
#print(soup)
week = soup.find(id='seven-day-forecast-body')

items = week.find_all(class_='tombstone-container')


period_names = [items.find(class_='period-name').get_text() for item in items]
short_descriptions = [items.find(class_='short-desc').get_text() for item in items]
temperatures = [items.find(class_='temp').get_text() for item in items]

print(period_names)
print(short_descriptions)
print(temperatures)
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5 Answers

0 votes
by (640 points)
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Best answer

The code you shared aims to detect faces in images using OpenCV's Haar cascade classifier. However, if the code is not functioning as expected, there could be a few potential issues causing the problem. To address this, you can follow these troubleshooting steps:

  1. Verify the XML file: Ensure that the haarcascade_frontalface_default.xml file exists in the same directory as your script. The code relies on this XML file to perform face detection. Double-check the file's presence and ensure it is correctly named and accessible.

  2. Check the availability of image files: Make sure there are PNG images in the same directory as your script. The code uses glob.glob('*.png') to retrieve all PNG images in the directory. If there are no PNG images present or if they are located in a different directory, the code will not be able to process any images.

  3. Validate OpenCV installation: Verify that OpenCV is properly installed in your Python environment. You can do this by running import cv2 in a separate Python script or in an interactive Python shell. If OpenCV is not installed, you can install it using pip install opencv-python.

  4. Debug the detection loop: To identify potential issues within the loop, you can insert print statements to inspect the values. For example, you can print the value of timage to ensure the image file paths are correctly retrieved, and print the number of detected faces using len(face) to check if any faces are being detected.

Here is the code for this:

import cv2

import glob

gimage = glob.glob('*.png')

detect = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')

for timage in gimage:

    print("Processing image:", timage)

    image = cv2.imread(timage)

    grayimg = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)

    face = detect.detectMultiScale(grayimg, 1.25, 3)

    print("Number of faces detected:", len(face))

    for (x, y, w, h) in face:

        cv2.rectangle(image, (x, y), (x + w, y + h), (0, 255, 0), 2)

    cv2.imshow('Detecting image', image)

    cv2.waitKey(2000)

    cv2.destroyAllWindows()

By applying these modifications and executing the code, you will gain more insights into any potential issues and be able to debug the face detection process. Please let me know if you encounter any further difficulties or require additional assistance.

0 votes
by (1.3k points)

The error you encountered in the provided code is due to a mistake in how you are accessing the elements in the items list. The issue lies in the lines where you are trying to retrieve specific elements using find() inside a list comprehension. To fix this error, you need to modify those lines as follows:

period_names = [item.find(class_='period-name').get_text() for item in items] short_descriptions = [item.find(class_='short-desc').get_text() for item in items] temperatures = [item.find(class_='temp').get_text() for item in items]

By replacing items.find() with item.find() in each line, you correctly access the individual elements in the items list.

Here's the modified code:

import requests

from bs4 import BeautifulSoup

page = requests.get('https://forecast.weather.gov/MapClick.php?lat=45.2541&lon=-113.2262#.Xn8kMIgzZPY')

soup = BeautifulSoup(page.content, 'html.parser')

week = soup.find(id='seven-day-forecast-body')

items = week.find_all(class_='tombstone-container')

period_names = [item.find(class_='period-name').get_text() for item in items]

short_descriptions = [item.find(class_='short-desc').get_text() for item in items]

temperatures = [item.find(class_='temp').get_text() for item in items]

print(period_names)

print(short_descriptions)

print(temperatures)

With these modifications, the code should execute correctly without raising the AttributeError and provide the desired output of period names, short descriptions, and temperatures.
0 votes
by (640 points)

The AttributeError you encountered in the provided code occurs due to incorrectly accessing elements in the items list. The issue lies in using find() instead of item.find() within the list comprehension. To resolve this error, you should make the following adjustments:

period_names = [item.find(class_='period-name').get_text() for item in items] short_descriptions = [item.find(class_='short-desc').get_text() for item in items] temperatures = [item.find(class_='temp').get_text() for item in items]

By replacing items.find() with item.find() in each line, you ensure that you're accessing the individual elements within the items list correctly.

Here is the complete code:

import requests

from bs4 import BeautifulSoup

page = requests.get('https://forecast.weather.gov/MapClick.php?lat=45.2541&lon=-113.2262#.Xn8kMIgzZPY')

soup = BeautifulSoup(page.content, 'html.parser')

week = soup.find(id='seven-day-forecast-body')

items = week.find_all(class_='tombstone-container')

period_names = [item.find(class_='period-name').get_text() for item in items]

short_descriptions = [item.find(class_='short-desc').get_text() for item in items]

temperatures = [item.find(class_='temp').get_text() for item in items]

print(period_names)

print(short_descriptions)

print(temperatures)

With these modifications, the code should run without raising the AttributeError and provide the expected output, which includes the period names, short descriptions, and temperatures.

0 votes
by (300 points)

The AttributeError encountered in the provided code is a result of incorrect access to elements within the items list. The issue arises from using find() instead of item.find() within the list comprehension. To rectify this error, the following adjustments should be made:

period_names = [item.find(class_='period-name').get_text() for item in items] short_descriptions = [item.find(class_='short-desc').get_text() for item in items] temperatures = [item.find(class_='temp').get_text() for item in items]

By replacing items.find() with item.find() in each line, the individual elements within the items list are accessed correctly.

import requests

from bs4 import BeautifulSoup

page = requests.get('https://forecast.weather.gov/MapClick.php?lat=45.2541&lon=-113.2262#.Xn8kMIgzZPY')

soup = BeautifulSoup(page.content, 'html.parser')

week = soup.find(id='seven-day-forecast-body')

items = week.find_all(class_='tombstone-container')

period_names = [item.find(class_='period-name').get_text() for item in items]

short_descriptions = [item.find(class_='short-desc').get_text() for item in items]

temperatures = [item.find(class_='temp').get_text() for item in items]

print(period_names)

print(short_descriptions)

print(temperatures)

By implementing these adjustments, the code will execute without raising the AttributeError and produce the desired output, consisting of the period names, short descriptions, and temperatures.

0 votes
by (300 points)

Here are the steps to troubleshoot the code:

  1. Verify the XML file: Ensure that the haarcascade_frontalface_default.xml file exists in the same directory as your script. This XML file is essential for face detection. Double-check its presence, correct naming, and accessibility.

  2. Check image file availability: Make sure there are PNG images in the same directory as your script. The code uses glob.glob('*.png') to retrieve PNG images from the directory. Without any PNG images or if they are located elsewhere, the code won't process any images.

  3. Validate OpenCV installation: Confirm that OpenCV is properly installed in your Python environment. Run import cv2 in a separate Python script or an interactive Python shell to verify the installation. If OpenCV is missing, use pip install opencv-python to install it.

  4. Debug the detection loop: Add print statements to the loop for inspecting values. For example, printing the value of timage will ensure correct image file paths, while printing len(face) will indicate the number of detected faces.

Here's the modified code with troubleshooting modifications:

import cv2 import glob gimage = glob.glob('*.png') detect = cv2.CascadeClassifier('haarcascade_frontalface_default.xml') for timage in gimage: print("Processing image:", timage) image = cv2.imread(timage) grayimg = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY) face = detect.detectMultiScale(grayimg, 1.25, 3) print("Number of faces detected:", len(face)) for (x, y, w, h) in face: cv2.rectangle(image, (x, y), (x + w, y + h), (0, 255, 0), 2) cv2.imshow('Detecting image', image) cv2.waitKey(2000) cv2.destroyAllWindows()

By following these modifications, you will gain insights into potential issues and be able to debug the face detection process. Let me know if you require further assistance or encounter any difficulties.

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