#方法一:
import re
f = open('纠正字母i', 'r', encoding='utf-8')
s = f.read()
ret = re.subn('I', 'i', s)
s = ret[0]
print(s)
#方法二
sum = s.count('I') b = s.replace('I', 'i', sum) print(b)
#方法三:
b = [] for a in s: if a == 'I': b.append("i") else: b.append(a) s = ''.join(b)