如何获取python中2个字符串之间的公共有序字符？

Question

How to get the common ordered characters between 2 strings in python?

for example:

str1 = 'AAA'
str2 = 'AXA'

output should be 'AA'

Answer 1

Compare each characters from 2 strings and keep it when they are the same:

str1 = 'AAA'
str2 = 'AXA'

str3 = ''.join(c1 for c1, c2 in zip(str1, str2) if c1 == c2)
print(str3)

# Output
'AA'

Other example:

str1 = 'ABC'
str2 = 'AZB'

str3 = ''.join(c1 for c1, c2 in zip(str1, str2) if c1 == c2)
print(str3)

# Output
'A'

Answer 2

Try like this

result = ''
for i in range(0, len(str1)):
    if str1[i] == str2[i]:
       result += str1[i]

print(result)