I have a column of positive and negative number. How to convert this column to a new column to realize convert positive number to 1 and negative number to -1?
You need numpy.sign
df['new'] = np.sign(df['col'])
Sample :
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
It's really easy to perform this task by -
For whole data frame -
df[df < 0] = -1
df[df > 0] = 1
For specific column -
df['column_name'][df['column_name'] < 0] = -1
df['column_name'][df['column_name'] > 0] = 1
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.