Fix potential issues if str has spaces

Uniform the split() function
str.split() will return a list split all spaces in str,
while str.split(' ') will return a list might contain ''
which might have potential issues.

Signed-off-by: jiajia tang <tangjiajia@xiaomi.com>
Change-Id: I0961659b140f800bdbe285f63bb4f02b8459ff8b
Signed-off-by: jiajia tang <tangjiajia@xiaomi.com>