python - Pandas 阅读html表格

Question

import pandas as pd
import pandas_datareader.data as web

coins = pd.read_html('https://coinmarketcap.com/')

for name in coins[0][1][1:]:
    print(name)

导致以下错误消息。当我打印硬币时，我得到了完整的表格，但是当我尝试获取特定信息时，它给了我这个错误信息。我知道这种格式有效，因为我从我一直在学习的其他练习中完全复制了它，并且刚刚更改了网站。非常感谢。

C:\Users\AppData\Local\Programs\Python\Python36-32\python.exe C:/Users/Desktop/python_work/crypto/crypto_corr.py
Traceback (most recent call last):
  File "C:\Users\AppData\Local\Programs\Python\Python36-32\lib\site-packages\pandas\core\indexes\base.py", line 2525, in get_loc
    return self._engine.get_loc(key)
  File "pandas\_libs\index.pyx", line 117, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\index.pyx", line 139, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\hashtable_class_helper.pxi", line 1265, in pandas._libs.hashtable.PyObjectHashTable.get_item
  File "pandas\_libs\hashtable_class_helper.pxi", line 1273, in pandas._libs.hashtable.PyObjectHashTable.get_item
KeyError: 1

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:/Users/Desktop/python_work/crypto/crypto_corr.py", line 6, in <module>
    for name in coins[0][1][1:]:
  File "C:\Users\AppData\Local\Programs\Python\Python36-32\lib\site-packages\pandas\core\frame.py", line 2139, in __getitem__
    return self._getitem_column(key)
  File "C:\Users\AppData\Local\Programs\Python\Python36-32\lib\site-packages\pandas\core\frame.py", line 2146, in _getitem_column
    return self._get_item_cache(key)
  File "C:\Users\AppData\Local\Programs\Python\Python36-32\lib\site-packages\pandas\core\generic.py", line 1842, in _get_item_cache
    values = self._data.get(item)
  File "C:\Users\AppData\Local\Programs\Python\Python36-32\lib\site-packages\pandas\core\internals.py", line 3843, in get
    loc = self.items.get_loc(item)
  File "C:\Users\AppData\Local\Programs\Python\Python36-32\lib\site-packages\pandas\core\indexes\base.py", line 2527, in get_loc
    return self._engine.get_loc(self._maybe_cast_indexer(key))
  File "pandas\_libs\index.pyx", line 117, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\index.pyx", line 139, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\hashtable_class_helper.pxi", line 1265, in pandas._libs.hashtable.PyObjectHashTable.get_item
  File "pandas\_libs\hashtable_class_helper.pxi", line 1273, in pandas._libs.hashtable.PyObjectHashTable.get_item
KeyError: 1

Process finished with exit code 1

Answer 1

如果 df 是一个数据帧，像 df[column] 这样的索引会查找名为 column 的 columns。在您的例子中，coins[0] 是一个数据框，它没有列 1。但是，它确实有一列 Name，因此要打印所有名称，请执行以下操作:

df = coins[0]
for name in df['Name']:
    print(name)