Write a function to remove lowercase substrings from a given string.
import re
def remove_lowercase(str1):
 remove_lower = lambda text: re.sub('[a-z]', '', text)
 result =  remove_lower(str1)
 return result
<s>[INST]<<SYS>>Given a task and its code, generate test cases for the code.<</SYS>>Write a function to remove lowercase substrings from a given string.
import re
def remove_lowercase(str1):
 remove_lower = lambda text: re.sub('[a-z]', '', text)
 result =  remove_lower(str1)
 return result[/INST]assert remove_lowercase("PYTHon")==('PYTH')
assert remove_lowercase("FInD")==('FID')
assert remove_lowercase("STRinG")==('STRG')</s>