Python lambda expression simple usage

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# General conditions Statement if   1 = = 1:      name =  ' Wupeiqi ' else : &NBSP;&NBSP;&NBSP;&NBSP; name =  ' Alex '    # ternary operations ' Wupeiqi '  if  < Code class= "Bash plain" >1 = = 1  else

For simple functions, there is also an easy way to express that: lambda expression

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# ######### ############# normal function ###################### # define function (Normal mode) def func (ARG): &NBSP;&NBSP;&NBSP;&NBSP; return  arg + 1    # execute function result = func (123) Code class= "Bash Spaces" >   # ###################### Lambda ########### ###########    # define function (lambda expression) my_lambda = lambda Arg:arg + 1    < Code class= "Bash comments" ># execute function result = MY_LAMBDA (123)

The existence of Lambda means a concise representation of simple functions

Built-in function two

First, Map

Iterates through the sequence, operates on each element of the sequence, and finally gets a new sequence.

Li = [one, one, 33]new_list = map (lambda a:a + li)

Li = [one, 33]SL = [1, 2, 3]new_list = map (lambda A, b:a + B, Li, SL)

Second, filter

Filter the elements in a sequence, and finally get a sequence that matches the criteria

Li = [one, one, 33]new_list = filter (lambda arg:arg > P, li) #filter第一个参数为空, the original sequence will be obtained

Third, reduce

Cumulative operation for all elements within a sequence

Li = [one, three, 33]result = reduce (lambda arg1, Arg2:arg1 + Arg2, Li) # The first argument of reduce, the function must have two parameters # reduce the second parameter, to loop the sequence # reduce The third parameter, the initial value

Python lambda expression simple usage