Python's own function map (), zip (), etc.

1.map () function

The purpose of the map () function is to perform a function operation on each member iteration and finally return a list

Map (function, sequence[, sequence, ...]) list

In [add100]: def (x): ....: Return x+100 ...: in [the]: Map (add100, (44,22,66)) out[83]: [144, 122, 166]

Defining a function add100 (x), Map (add100, (44,22,66)) is the iterative operation of ADD100 (x) for each number, and finally returns a list of data

in [+]: def ABC (A,B,C): ....: return a*100 + b*10 + C ....: in []: Map (ABC, (), (4,5,6), (7,8,9)) out[85]: [14 7, 258, 369]

If you need more than one parameter for a function that needs to be executed by iteration, provide multiple tuples for map ()

In []: Map (None,range (3)) out[91]: [0, 1, 2]in []: Map (None,range (3)) out[92]: [0, 1, 2]in []: Map (None,range (3), ' abc ') , (44,55,66)) out[93]: [(0, ' a ', 0), (1, ' B ', 1), (2, ' C ',)]in [94]: Map (None,range (3), ' abc ') OUT[94]: [(, ' a '), (, ' B '), (2, ' C ')]in [+]: Map (None,range (3), Range (3)) out[95]: [(0, 0), (1, 1), (2, 2)]

You can do this if you want to convert a line of strings into a dictionary.

In [the]: d= ' zk_version\t3.4.6 ' in []: Map (str.strip,d.split (' t ')) out[99]: [' zk_version ', ' 3.4.6 ']in []: Key,value =map (Str.strip,d.split (' t ')) in [101]: keyout[101]: ' zk_version ' in [102]: valueout[102]: ' 3.4.6 ' in [103]: result[key]= Valuein [104]: resultout[104]: {' zk_version ': ' 3.4.6 '}

2.zip () function

The purpose of the zip () is to return a list of tuples

Zip (seq1 [, SEQ2 [...]]), [(Seq1[0], seq2[0] ...), (...)

In [107]: L1=[1,2,3,4]in [108]: l2=[' A ', ' B ', ' C ', ' d ']in [109]: Zip (L1,L2) out[109]: [(1, ' a '), (2, ' B '), (3, ' C '), (4, ' d ')] in [+]: L3=[10.0,20.0,30.0,40.0]in [111]: Zip (L1,L2,L3) out[111]: [(1, ' a ', 10.0), (2, ' B ', 20.0), (3, ' C ', 30.0), (4, ' d ', 40.0)]

3.dict () function

Dict () The last returned is a dictionary type

In [141]: l1out[141]: [1, 2, 3, 4]in [142]: l2out[142]: [' A ', ' B ', ' C ', ' d ']in [143]: Zip (L2,L1) out[143]: [(' A ', 1], (' B ', 2), (' C ', 3), (' d ', 4)]in [144]: Dict (Zip (L2,L1)) out[144]: {' A ': 1, ' B ': 2, ' C ': 3, ' d ': 4}in [145]: Dict (a=10,b=20,c=30) OUT[145]: {' A ': ten, ' B ': +, ' C ': 30}in [146]: Dict [(' A ', ' + '), (' B ', ' + ')]) out[146]: {' A ': +, ' B ': $, ' C ': 30 0}

Resources:

Https://docs.python.org/2/library/functions.html#zip

Http://stackoverflow.com/questions/672172/using-python-map-and-other-functional-tools

Https://infohost.nmt.edu/tcc/help/pubs/python/web/map-function.html

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Python's own function map (), zip (), etc.