Python map () function

Source: Internet
Author: User

" " seek the 1+2!+3!+...+20! and.  "l=range (1,21)def  op (x): R=1 for in Range (1,x +1): R*=Ireturn  rs# Note Map operation print(  "1!+2!+3!+...+20!=%ld"% (s))

Map () is a Python built-in high-order function that receives a function f and a list, and then, by putting the function f on each element of the list in turn, gets a new list and returns.

For example, for list [1, 2, 3, 4, 5, 6, 7, 8, 9]

If you want to square each element of the list, you can use the map () function:

Therefore, we only need to pass in the function f (x) =x*x, we can use the map () function to complete this calculation:

def f (x):
Return x*x
Print map (f, [1, 2, 3, 4, 5, 6, 7, 8, 9])
Output Result:

[1, 4, 9, 10, 25, 36, 49, 64, 81]
Note: the map () function does not change the original list, but instead returns a new list.

With the map () function, you can convert a list to another list, just pass in the conversion function.

Because the list contains elements that can be of any type, map () can not only handle lists that contain only numeric values, but in fact it can handle lists of any type, as long as the incoming function f can handle the data type.

Task
Assuming that the user entered the English name is not standard, not according to the first letter capitalization, subsequent letter lowercase rules, please use the map () function, a list (including a number of nonstandard English names) into a list containing the canonical English name:

Input: [' Adam ', ' LISA ', ' BarT ']
Output: [' Adam ', ' Lisa ', ' Bart ']

" "Assuming that the user entered the English name is not standardized, not according to the first letter uppercase, followed by the letter lowercase rules, use the map () function, a list (including a number of nonstandard English names) into a list containing the canonical English name: input: [' Adam ', ' LISA ', ' Bart '] output: [' Adam ', ' Lisa ', ' Bart ']" "defFormatName (s): S1=s[0:1].upper () +s[1:].lower (); returnS1; NameList=["Adam","LISA","BarT"]Print(FormatName ("Adam"))#In Python3, to get the list generated by the map, you need to add a list () in front of the mapPrint(List (Map (formatname,['ABC','Deff','AAAA'])))

Reference Blog: http://www.cnblogs.com/superxuezhazha/p/5714970.html

Python map () function

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