string

print('#1. replace')
print('hello world'.replace('hello', 'Hello'))
print('hello world'.replace('hello1', 'Hello'))

print('\n#2. translate')
table = str.maketrans('abcde','12345')
print('abcdefghijk'.translate(table))

print('\n#3. split')
print('kim park lee kang choi'.split())

print('\n#4. join')
print(' '.join(['kim', 'park', 'lee', 'kang', 'choi']))

print('\n#5. upper')
print('python'.upper())

print('\n#6. lower')
print('PYTHON'.lower())

print('\n#7. lstrip')
print('Start', '     Python  '.lstrip(), 'End', sep='')
print('Start', ', Python.'.lstrip(',.'), 'End', sep='')

print('\n#8. rstrip')
print('Start', '     Python  '.rstrip(), 'End', sep='')
print('Start', ', Python.'.rstrip(',.'), 'End', sep='')

print('\n#9. strip')
print('Start', '     Python  '.strip(), 'End', sep='')
print('Start', ', Python.'.strip(',.'), 'End', sep='')


=====Result====
#1. replace
Hello world
hello world

#2. translate
12345fghijk

#3. split
['kim', 'park', 'lee', 'kang', 'choi']

#4. join
kim park lee kang choi

#5. upper
PYTHON

#6. lower
python

#7. lstrip
StartPython  End
Start Python.End

#8. rstrip
Start     PythonEnd
Start, PythonEnd

#9. strip
StartPythonEnd
Start PythonEnd