Python xpath:尝试xpath,但填写给定值除外

try / except ,只需尝试获取两个包含所有必需元素的列表,如下所示:

html = lxml.html.fromstring("source code here")
reviews = html.xpath('//div[@class="rating reviewItemInline"]')
dates = [i.xpath('./span[@class="ratingDate relativeDate"]')[0].text for i in reviews]
mobile = [i.xpath('./a')[0].text if i.xpath('./a') else "no" for i in reviews]
output = [{'date': i, 'via mobile': j} for i, j in zip(dates, mobile)]

output 应该是这样的

[{'date': 'Reviewed 6 days ago', 'via mobile': 'via mobile'}, {'date': 'Reviewed 6 days ago', 'via mobile': 'no'}]

review_elems = tree_html.xpath('//div[@class="rating reviewItemInline"]')

reviews = []   

for review_elem in reviews_elems:
    review = {}
    username = review_elem.xpath('.//a[@class="viaMobile"]')
    if username:
        review['username'] = username[0].text
    else:
        review['username'] = 'no name'

    # keep filling review with more fields
    reviews.append(review)

print(reviews)