我正在尝试使用 pandas 在 python 中为 SuperTrend 指标编写以下算法。
BASIC UPPERBAND = (HIGH + LOW) / 2 + Multiplier * ATR
BASIC LOWERBAND = (HIGH + LOW) / 2 - Multiplier * ATR
FINAL UPPERBAND = IF( (Current BASICUPPERBAND < Previous FINAL UPPERBAND) or (Previous Close > Previous FINAL UPPERBAND))
THEN (Current BASIC UPPERBAND) ELSE Previous FINALUPPERBAND)
FINAL LOWERBAND = IF( (Current BASIC LOWERBAND > Previous FINAL LOWERBAND) or (Previous Close < Previous FINAL LOWERBAND))
THEN (Current BASIC LOWERBAND) ELSE Previous FINAL …我正在尝试以下代码
df = pd.DataFrame([[23, 52], [36, 49], [52, 61], [75, 82], [97, 12]], columns=['A', 'B'])
df['C'] = np.where(df['A'] > df['C'].shift(), df['A'], df['C'].shift())
print(df)
假设第一个df['C].shift()操作应假设为0(因为df['C']不存在)
预期产出
A B C
0 23 52 23
1 36 49 36
2 12 61 36
3 75 82 75
4 70 12 75
但我得到一个KeyError异常.
Traceback (most recent call last):
File "C:\Program Files\Python36\lib\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 …