string='abcde'
x=string.find('a')
y=string.find('bc')
z=string.find('f')
print(x)
print(y)
print(z)
#运行结果
0
1
-1

string='abcde'
x=string.index('a')
y=string.index('bc')
#z=string.index('f')
print(x)
print(y)
#print(z)
0
1
ValueError: substring not found

lis=['a','b','c','d','e']
string='abcde'
tup=('a','b','c','d','e')
print(''.join(lis))
print(' '.join(string))
print('$'.join(tup))
#运行结果
abcde
a b c d e
a$b$c$d$e

string='this is an interesting story!'
a=string.split()
b=string.split(' ',2)
c=string.split('s')
d=string.split(',')
print(a)
print(b)
print(c)
print(d)
#运行结果
['this', 'is', 'an', 'interesting', 'story!']
['this', 'is', 'an interesting story!']
['thi', ' i', ' an intere', 'ting ', 'tory!']
['this is an interesting story!']

string='**this is an ***interesting story!***'
a=string.strip('*')
b=string.lstrip('*')
c=string.rstrip('*')
print(string)
print(a)
print(b)
print(c)
#运行结果
**this is an ***interesting story!***
this is an ***interesting story!
this is an ***interesting story!***
**this is an ***interesting story!