Python：字符串处理函数

Posted 2020-11-06 KumataのBloG

Split & Combine  #拆分和组合

#split() 通过指定分隔符对字符串进行切片
lan = "python ruby c c++ swift"
lan.split()
[‘python‘, ‘ruby‘, ‘c‘, ‘c++‘, ‘swift‘]

todos = "download python, install, download ide, learn"
todos.split(‘, ‘)
[‘download python‘, ‘install‘, ‘download ide‘, ‘learn‘]

‘,‘.join([‘download python‘, ‘install‘, ‘download ide‘, ‘learn‘])
‘download python,install,download ide,learn‘

 

Substitue #替换

#replace()
s = ‘I like C. I like C++. I like Python‘
s.replace(‘like‘, ‘hate‘)
‘I hate C. I hate C++. I hate Python‘

s.replace(‘like‘, ‘hate‘, 1)
‘I hate C. I like C++. I like Python‘

Layout #布局

align = ‘Learn how to align‘
align.center(30)
‘      Learn how to align      ‘

align.ljust(30)
‘Learn how to align            ‘

align.rjust(30)
‘            Learn how to align‘

ralign = align.rjust(30)
ralign.strip()
‘Learn how to align‘

 

Other useful tools

py_desc = "Python description: Python is a programming language that lets you work quickly and integrate systems more effectively."
py_desc.startswith(‘Python‘)
True

py_desc.endswith(‘effectively.‘)
True

py_desc.find(‘language‘)
44

py_desc.isalnum()
False

py_desc.count("Python")
2

py_desc.strip(‘.‘)
‘Python description: Python is a programming language that lets you work quickly and integrate systems more effectively‘

py_desc.upper()
‘PYTHON DESCRIPTION: PYTHON IS A PROGRAMMING LANGUAGE THAT LETS YOU WORK QUICKLY AND INTEGRATE SYSTEMS MORE EFFECTIVELY.‘

py_desc.title()
‘Python Description: Python Is A Programming Language That Lets You Work Quickly And Integrate Systems More Effectively.‘

 

New style in Python 3.6

print(‘%s %s‘ % (‘one‘, ‘two‘))
print(‘{} {}‘.format(‘one‘, ‘two‘))
print(‘%d %d‘ % (1, 2))
print(‘{} {}‘.format(1, 2))
one two
one two
1 2
1 2

print(‘{1} {0}‘.format(‘one‘, ‘two‘))
two one

a = 5
b = 10
print(f‘Five plus ten is {a + b} and not {2 * (a + b)}.‘)
Five plus ten is 15 and not 30.

name = "Joshua"
question = "hello"
print(f"Hello, {name}! How‘s it {question}?")
Hello, Joshua! How‘s it hello?