python 字符串替换 拼接，比较

# 替换
s = 'hello,python'
print(s.replace('python','java')) # hello,javas = 'hello,python,python,python'
print(s.replace('python','java',2)) #hello,java,java,python# 将列表或元祖合并为一个新的字符串
lst = ['hello','java','python']
lst1 = ('hello','java','python')
print('|'.join(lst)) # hello|java|python
print(''.join(lst)) # hello|java|python
print(''.join(lst1)) # hello|java|pythonprint('*'.join('python')) # p*y*t*h*o*n

hello,java
hello,java,java,python
hello|java|python
hellojavapython
hellojavapython
p*y*t*h*o*n

# 字符串比较操作
print('apple'>'app') #true
print(ord('a'),ord('b'))
print(chr(97),chr(98))print(chr(ord('飞')))
a = b = 'python'
c = 'python'
print(a == c)
print(a is c)
print(b == c)
print(id(a),id(b),id(c))

True
97 98
a b
飞
True
True
True
1740238251656 1740238251656 1740238251656