Python - Simliar to excel formula how to do the calculation for each rows in python/pandas by referr-CodePudding

data = {'Open': [7099,7089.3,7097.55,7365,7429, 7486.05], 'high': [ 7150,7169,7278.2,7410,7500,7520], 'low' : [7060,6884.85,7092.25,7344.15,7407,7443],
'close': [7104,7058.4,7269.1,7398.3,7489.45,7505.45]}

df1 = pd.DataFrame(data)

I want to calculate (open-close(previous row) in another column 'gap'. in Excel we can easily refer the previous cell to get the out put as below C12-F11.

is anyway to achieve this without using loop ? similar to numpy function np.where()

df1["open=high"] = np.where (df1['open'] == df1 ['high'], 'Y', 'N')

CodePudding user response：

You can use shift:

df1['Gap'] = df1.Open - df1.close.shift()

df1
      Open    high      low    close    Gap
0  7099.00  7150.0  7060.00  7104.00    NaN
1  7089.30  7169.0  6884.85  7058.40 -14.70
2  7097.55  7278.2  7092.25  7269.10  39.15
3  7365.00  7410.0  7344.15  7398.30  95.90
4  7429.00  7500.0  7407.00  7489.45  30.70
5  7486.05  7520.0  7443.00  7505.45  -3.40