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1.type () to test the type of a variable. int is a numeric variable, str is a character variable
name = "yao" Year = 1993 print( name + str(Year))
>>yao1993
2.ord () is a built-in function to return a character,
chr () is based on integer worth to the corresponding character.
print(ord("a")) print(chr(97)) >>97 >>a
3. The strings are many ways you can () to view the dir
print(dir(str))
>>
['__add__', '__class__', '__contains__', '__delattr__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__getnewargs__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__iter__', '__le__', '__len__', '__lt__', '__mod__', '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__rmod__', '__rmul__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', 'capitalize', 'casefold', 'center', 'count', 'encode', 'endswith', 'expandtabs', 'find', 'format', 'format_map', 'index', 'isalnum', 'isalpha', 'isascii', 'isdecimal', 'isdigit', 'isidentifier', 'islower', 'isnumeric', 'isprintable', 'isspace', 'istitle', 'isupper', 'join', 'ljust', 'lower', 'lstrip', 'maketrans', 'partition', 'replace', 'rfind', 'rindex', 'rjust', 'rpartition', 'rsplit', 'rstrip', 'split', 'splitlines', 'startswith', 'strip', 'swapcase', 'title', 'translate', 'upper', 'zfill']
4. Case conversion
name.swapcase () # lowercase variable capital, uppercase to lowercase name.capitalize () # capitalized name.upper () # ALL CAPS name.lower () # all lowercase name.title () # the first letter in all caps
The retrieval of a position of the character in the string
name.find ( " the n- " ) # locate the "n" where, starting from 0 name.index ( " the n- " ) # retrieve elements in a variable position, starting from 0
6. The number of times a search of a character string appearing in
print (name.count("n"))
7. Check the string length
print (len (name))
8. power
pow (x, y) = x ** y = y x to the power
9. absolute value
print(bas(-2)) >>2
10. take the remainder
Print (. 5%. 3 ) >> 2 Print (divmod (5,3 )) # take quotient and the remainder ( 1,2)
11. The maximum or minimum
Print (max (, 2, 3)) # maximum
>> 3
12. integer, floating point, and a plurality
int (x) # x to become an integer, fractional part is discarded a float (x) # x to become floating point, increase the fractional part Complex (x) # x to become complex, increasing the imaginary part
13. rounding
= 5.453 X
Print (round (X, 2)) # round (X, D) are reserved several decimal places D
14. A space or line breaks removed
= name " \ nYao \ n- " Print (name.lstrip ()) # removed or left line feed space
print (name.rstrip ()) # remove the right line feed
print (name.strip ()) # remove all newline symbol
15. Analyzing
Print ( ' AG12 ' .isalnum ()) # determines whether or not composed of numbers and letters Print ( ' AG ' .isalpha ()) # determines whether only the letter Print ( ' 2 ' .isdigit ()) # determines whether only integer
print ( '1'.isdecimal ()) # decimal determines whether
print (' a-1R'.isidentifier () ) # determines whether a qualified variable name or identifier, i.e., there are special characters not only have integer and the letter
print ( 'My Name'.istitle ()) # determines whether all capital letters
16. filling
Print (name.center (50, '% ' )) # 50 to a width, with less than '%' is filled, name the intermediate
print (name.ljust (50, '% ')) # % less than with up behind fill
print (name. rjust (50, '%')) #% with less than fill, fill front
17. Replace
str.maketrans = p ( ' ABC ' , ' 123 ' ) # p-replacement rules for producing, Print ( ' adbce ' .translate (p)) # was then replaced with Translate Print ( ' ALEXA ' .replace ( ' A ' , ' A ' ,. 1)) # . 1 showing several alternative
18. A splice, connector
1.split # return a list of B = ' www.baidu.com ' C = b.split ( ' . ' ) Print (C) >> [ ' WWW ' , ' baidu ' , ' COM ' ] 2 .join C = [ ' WWW ' , ' baidu ' , ' COM ' ] D = ' * ' . join(c) print(d) >> www * baidu * com
19. The list is sorted, temporary sort, reverse list
= A [7,2,4,3,1 ] a.sort () # default from small to large, (reverse = True) descending
Print (A)
Print (the sorted (A)) # temporary sort
print (a )
>> [1, 2, 3, 4, 7]
>>[7, 2, 4, 3, 1]
a.reverse () # reverse list
20. The modified list elements
Name = ['xiao','da','max'] Name[0] = 'You' print(Name) >>['You', 'da', 'max']
21. Insert and additive elements
# Insert elements the Name = [ ' Xiao ' , ' DA ' , ' max ' ] Name.insert (0, ' the Apple ' ) Print (the Name) >> [ ' the Apple ' , ' Xiao ' , ' DA ' , ' max ' ] # additive element Name.append ( ' Blue ' )
22. Removing elements
= The Name [ ' xiao ' , ' DA ' , ' max ' ] del the Name [0] # according to the index to delete Print (the Name) Print (Name.pop ()) # can delete the end of the list of elements, and so that you can use to delete elements # may be added index POP (. 1) Print (the Name) >> max >> [ ' Xiao ' , ' DA ' ] Name.remove ( ' DA ' ) # position is not known, can remove ()
23./n newline, / t tab, / r carriage return, / b backoff