Today I completed 24th Day of #100DayOfcode and #python. Today I also revised python basic with the help of internet and Youtube.
Tried to write some code in python.
New things today I learned were python iterator, python map, python filter, python reduce on youtube and with the help of friend. some simple code today I learned given below.
Python iterator is an object that can be iterated upon meaning that we can traverse through all the values. Technically, in python , an iterator is an object which implements the iter protocal, which consists of the method
class TopTen: def __init__(self): self.num = 1 def __iter__(self): return self def __next__(self): if self.num <= 10: val = self.num self.num += 1 return val values = TopTen() print(values.__next__()) print(values.__next__())
The map() function executes a specified function for each item in an iterable. The item is sent to the function as a parameter.
numbers = (1, 2, 3, 4) result = map(lambda x: x*x, numbers) print(result) numbersSquare = set(result) print(numbersSquare)
The filter() method constructs an iterator from elements of an iterable for which a function return true.
In simple words, filter() method filters the given iterable with the help of a function that test each element in the iterable to be true or not.
def is_even(n): return n % 2 == 0 nums = [2,3,4,6,8,6,5,7] evens =list( filter(is_even,nums)) print(evens)
The reduce (fun, seq) function is used to apply a particular function passed in its argument to all of the list elements mentioned in the sequence passed along. This function is defined in "functools" module.
from functools import reduce nums = [2,3,4,6,8,6,5,7] evens =list( filter(lambda n : n% 2 ==0,nums)) double =list(map(lambda n : n*2,evens)) sum = reduce(lambda a, b : a+b ,double) #print(double) print(sum)