Python learning notes-string

Python learning notes-string

Today, I learned about Python's basic processing of strings, and I feel it will be helpful for automated scripts in my work to send CLI commands.

First, the most important thing is %, which is the nominal "conversion specifier" for string formatting.

Place a string (formatted string) on the left and the value to be formatted (value to be formatted) on the right)

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left = "Hello,%s good " # % S indicates the type to be formatted right = "she's"Print left % right # % is used to separate the formatted string from the value to be formatted. Hello,she's good

NOTE: If s is not added after %, the program reports an error

TypeError: float argument required, not str

If right is not a string, str is used to convert it into a string.

1234	print "Price of eggs: $%d" %42 print "Price of eggs in HEX: $%x" %42 Price of eggs: $42Price of eggs in HEX: $2a

In addition, the string module also provides many useful methods, such as the subsutitute method in the Template to replace the string.

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from string import Templatess=Template("$x loves some one")print (s.substitute(x='she'))print s she loves some one 0x105bc1350 >

The first print is the replaced string, and the second print is the template.

The following methods are commonly used for string operations:

• Find, equivalent to in

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  s="the best movie"print s.find('movie')print 'movie' in s print s.find('movie',10) # Provide the starting point from index10Start searchingprint s.find('movie',1,5) # Provide the start and end points from the index1Locate index59 True-1-1

  • Join & split, join and split string

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    from macpath import joins=[' ','root','home']print '//'.join(s)s1= 'C:' + '\\'.join(s)print s1 print s1.split('\\') //root//homeC: \root\home['C: ', 'root', 'home']

    Note that \ is used. If you only write \, the Program understands the special ASCII symbol \ r because the \ character is not the original character, press enter.

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    s1 = 'C:\root\home'print s1 C:oot\home

    So we use \ and escape characters \ to escape, that is, to tell the program \ is part of the string.

    Another way is to use the original string, which is not special to the backslash:

    
    

    123	s=[' ',r'root','home']print 'C:'+'/'.join(s)C: /root/home

    • Strip, remove characters on both sides of the string (the default is space)

    • Translate, which is the same as replace, but can be replaced at the same time, which is more efficient.

      For example, replace c in the string with k and s with z.

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      from string import maketranstable = maketrans('cs','kz') # Create a replacement rule tableprint len(table) print 'this is a magnificent day!'.translate(table,'!') # The second parameter is used to specify the characters to be deleted. 256 thiz iz a magnifikent day

      Divided by the upper and lower layers, there are lower, replace, capitalize and other uncommon methods.

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