问Python获取字符串和接下来的X行的位置

EN

example ='''This is an example string
That has multiple lines
With the words Your username is:
joe
normal
It should NOT grab this line
However it should detect the next line as it has
Your username is:
jane
also_normal
Do not grab this line'''
grab = False
line_count = 0
for line in example.split('\n'):
    if grab == True and line_count < 2:
        print (line)
        line_count +=1
    elif 'Your username is:' in line:
        grab = True
        line_count = 0
    else:
        grab = False
        line_count = 0

joe
normal
jane
also_normal

example ='''This is an example string
That has multiple lines
With the words Your username is: joe normal in the string
Program should grab this first line
And this second line and print
It should NOT grab this line
However it should detect the next line as it has
Your username is: joe normal
Grab this first line again
And grab this second line as well
Do not grab this line'''

grab = False
line_count = 0
for line in example.split('\n'):
    if grab == True and line_count < 2:
        print (line)
        line_count +=1
    elif 'Your username is: joe normal' in line:
        grab = True
        line_count = 0
    else:
        grab = False
        line_count = 0

Program should grab this first line
And this second line and print
Grab this first line again
And grab this second line as well

splittext = "Your username is: joe normal".split("Your username is:")
splittext.remove('')
for i in range(0, len(splittext)):
    splittext[i] = splittext[i][1:len(splittext[i])]

#returns joe normal