我有一列正面和负面的数字。如何将此列转换为新列以实现将正数转换为1而将负数转换为-1?
你需要numpy.sign
df['new'] = np.sign(df['col'])
样品:
df = pd.DataFrame({ 'col':[-1,3,-5,7,1,0]})
df['new'] = np.sign(df['col'])
print (df)
col new
0 -1 -1
1 3 1
2 -5 -1
3 7 1
4 1 1
5 0 0
df[df < 0] = -1
df[df > 0] = 1
//no behaviour defined for df = 0
通过以下方式执行此任务非常容易 -
对于整个数据框架 -
df[df < 0] = -1
df[df > 0] = 1
对于特定列 -
df['column_name'][df['column_name'] < 0] = -1
df['column_name'][df['column_name'] > 0] = 1