Python ValueError：int() 的无效文字，基数为 10：'196.41'
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ValueError: invalid literal for int() with base 10: '196.41'
提问by uzdisral
I don't understand why it works with different scenarios, but not with this one.
Basically, some gentleman helped me out HEREwith improving my code to scrape weather, which works perfectly. I then tried to do the same to scrape an ETH value which is in a span tag <span class="text-large2" data-currency-value="">$196.01</span>. So, I followed the same technique in the code, replaced the fields, and was hoping for it to work.
我不明白为什么它适用于不同的场景，但不适用于这个场景。基本上，一些绅士在这里帮助我改进了我的代码以刮取天气，这非常有效。然后我尝试做同样的事情来刮取 span 标签中的 ETH 值<span class="text-large2" data-currency-value="">$196.01</span>。所以，我在代码中采用了相同的技术，替换了字段，并希望它能够工作。
The code is here:
代码在这里：
import requests
from BeautifulSoup import BeautifulSoup
import time
url = 'https://coinmarketcap.com/currencies/litecoin/'
def ltc():
while (True):
response = requests.get(url)
soup = BeautifulSoup(response.content)
price_now = int(soup.find("div", {"class": "col-xs-6 col-sm-8 col-md-4 text-left"}).find(
"span", {"class": "text-large2"}).getText())
print(u"LTC price is: {}{}".format(price_now))
# if less than 150
if 150 > price_now:
print('Price is Low')
# if more than 200
elif 200 < price_now:
print('Price is high')
if __name__ == "__main__":
ltc()
The output looks like this:
输出如下所示：
Traceback (most recent call last):
File "test2.py", line 24, in <module>
ltc()
File "test2.py", line 13, in ltc
"span", {"class": "text-large2"}).getText())
ValueError: invalid literal for int() with base 10: '196.01'
Then, I finally tried it this way; but from here I get false positives, but no errors. It prints whatever it wants
然后，我终于这样试过了；但从这里我得到误报，但没有错误。它打印任何它想要的
import requests
from bs4 import BeautifulSoup
import time
url = 'https://coinmarketcap.com/currencies/litecoin/'
def liteCoin():
while (True):
response = requests.get(url)
html = response.text
soup = BeautifulSoup(html, 'html.parser')
value = soup.find('span', {'class': 'text-large2'})
print(''.join(value.stripped_strings))
if 150 > value: # if less than 150
print('Price is Low!')
elif 200 < value: # if more than 200
print('Price is High')
else:
print('N/A')
time.sleep(5)
if __name__ == "__main__":
liteCoin()
Would the problem be that the value of the ETH has a $sign inside the span tag? And, that way the program doesn't know what to do with string?
问题是 ETH 的价值$在span tag. 而且，这样程序不知道如何处理字符串？
回答by Rob?
First, let's simplify your sample program:
首先，让我们简化您的示例程序：
>>> int('196.01')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ValueError: invalid literal for int() with base 10: '196.01'
One cannot convert the string '196.01'to an integer number.
不能将字符串转换为'196.01'整数。
Try this:
尝试这个：
>>> int(float('196.01'))
196
Moving from the simple back to the complex, we can do this:
从简单回到复杂，我们可以这样做：
#UNTESTED
price_now = int(float(soup.find("div", {"class": "col-xs-6 col-sm-8 col-md-4 text-left"}).find(
"span", {"class": "text-large2"}).getText()))
回答by Dan-Dev
You need to understand types in Python you are getting a float not an int and you need to cast the float to a string to print it. So there are two changes needed.
您需要了解 Python 中的类型，您得到的是浮点数而不是整数，您需要将浮点数转换为字符串以打印它。因此，需要进行两个更改。
price_now = float(soup.find("div", {"class": "col-xs-6 col-sm-8 col-md-4 text-left"}).find("span", {"class": "text-large2"}).getText())
print(u"LTC price is: {}".format(str(price_now)))
Outputs:
输出：
LTC price is: 195.44
LTC price is: 195.44
