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[英]Problem with retrieving the value of item in list/dictionary of objects in Python3
[英]retrieving dictionary/list from textfile python3
我想將“ coins_info.txt”中的一列值保存到程序中的列表變量中。 以下是“ coins_info.txt”的內容:
Name,ICO,Max,USD_ROI
Bitcoin,0.0,19535.7,N/A
Ethereum,0.0,1389.18,N/A
Ripple,0.0,3.6491,N/A
Bitcoin Cash,0.0,4091.7,N/A
EOS,0.99,21.4637,2068.05%
Litecoin,0.0,366.153,N/A
...
我想從“ coins_info.txt”中的每個硬幣中獲取ICO,並將其保存到如下所示的列表中:
icos = [0.0, 0.0, 0.0, 0.0, 0.99, 0.0, ...]
我嘗試了這段代碼:
import pandas as pd
df = pd.read_csv("coins_info.txt")
icos = df["ICO"].values.tolist()
但是我的代碼第4行出現了此錯誤:
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/pandas/core/indexes/base.py", line 2442, in get_loc
return self._engine.get_loc(key)
File "pandas/_libs/index.pyx", line 132, in pandas._libs.index.IndexEngine.get_loc (pandas/_libs/index.c:5280)
File "pandas/_libs/index.pyx", line 154, in pandas._libs.index.IndexEngine.get_loc (pandas/_libs/index.c:5126)
File "pandas/_libs/hashtable_class_helper.pxi", line 1210, in pandas._libs.hashtable.PyObjectHashTable.get_item (pandas/_libs/hashtable.c:20523)
File "pandas/_libs/hashtable_class_helper.pxi", line 1218, in pandas._libs.hashtable.PyObjectHashTable.get_item (pandas/_libs/hashtable.c:20477)
KeyError: 'ICO'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "temp.py", line 280, in <module>
init_max_prices("btc.txt", "init")
File "temp.py", line 212, in init_max_prices
icos = df["ICO"].values.tolist()
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/pandas/core/frame.py", line 1964, in __getitem__
return self._getitem_column(key)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/pandas/core/frame.py", line 1971, in _getitem_column
return self._get_item_cache(key)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/pandas/core/generic.py", line 1645, in _get_item_cache
values = self._data.get(item)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/pandas/core/internals.py", line 3590, in get
loc = self.items.get_loc(item)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/pandas/core/indexes/base.py", line 2444, in get_loc
return self._engine.get_loc(self._maybe_cast_indexer(key))
File "pandas/_libs/index.pyx", line 132, in pandas._libs.index.IndexEngine.get_loc (pandas/_libs/index.c:5280)
File "pandas/_libs/index.pyx", line 154, in pandas._libs.index.IndexEngine.get_loc (pandas/_libs/index.c:5126)
File "pandas/_libs/hashtable_class_helper.pxi", line 1210, in pandas._libs.hashtable.PyObjectHashTable.get_item (pandas/_libs/hashtable.c:20523)
File "pandas/_libs/hashtable_class_helper.pxi", line 1218, in pandas._libs.hashtable.PyObjectHashTable.get_item (pandas/_libs/hashtable.c:20477)
KeyError: 'ICO'
我該如何解決我的代碼?
您可以在熊貓中加載txt文件並將ICO列轉換為列表,這是完整的代碼:
import pandas as pd
df = pd.read_csv('coins_info.txt', sep=",", header=0)
icos =list(df['ICO'])
or
icos = df['ICO'].values.tolist()
輸出:
icos = [0.0, 0.0, 0.0, 0.0, 0.99, 0.0]
您的代碼與示例數據配合良好:
df = pd.read_csv("coins_info.txt")
print (df)
Name ICO Max USD_ROI
0 Bitcoin 0.00 19535.7000 NaN
1 Ethereum 0.00 1389.1800 NaN
2 Ripple 0.00 3.6491 NaN
3 Bitcoin Cash 0.00 4091.7000 NaN
4 EOS 0.99 21.4637 2068.05%
5 Litecoin 0.00 366.1530 NaN
icos = df["ICO"].values.tolist()
print (icos)
[0.0, 0.0, 0.0, 0.0, 0.99, 0.0]
所以問題是另外一回事。
KeyError:“ ICO”
表示沒有ICO
列。
首先檢查列名稱是否存在一些空格或類似的內容:
print (df.columns.tolist())
然后需要:
df.columns = df.columns.str.strip()
或另一個可能的問題是使用不同的分隔符作為默認的sep=','
。
然后需要:
df = pd.read_csv("coins_info.txt", sep=';')
icos = df["ICO"].values.tolist()
我想從“ coins_info.txt”中的每個硬幣中獲取ICO,並將其保存到如下所示的列表中...
對於孤立地完成此任務,熊貓可能會顯得過大。 您可以使用內置的csv模塊將您的列讀入列表:
import csv
from io import StringIO
mystr = StringIO("""Name,ICO,Max,USD_ROI
Bitcoin,0.0,19535.7,N/A
Ethereum,0.0,1389.18,N/A
Ripple,0.0,3.6491,N/A
Bitcoin Cash,0.0,4091.7,N/A
EOS,0.99,21.4637,2068.05%
Litecoin,0.0,366.153,N/A""")
# replace mystr with open('coins_info.txt', 'r')
with mystr as fin:
reader = csv.DictReader(fin)
ico_list = [float(row['ICO']) for row in reader]
print(ico_list)
[0.0, 0.0, 0.0, 0.0, 0.99, 0.0]
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