如何制作从1开始的N个连续奇数的列表

Question

I need to write a function that generates a list of n odd numbers, starting at 1. If input is 12, output should be [1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23] . If input is 10 , output should be [1, 3, 5, 7, 9, 11, 13, 15, 17, 19]

Answer 1

Almost..

def odd(n):
    nums = []
    for i in range(1, 2*n, 2):
        nums.append(i)
    return nums

we know that every other number is odd, so we have to "count" up to 2*n to include all of them. The range function takes a third argument that indicates how many elements to skip in each iteration.

Answer 2

def odd(n):
    return list(range(1, 2*n, 2))

print(odd(10))
print(odd(12))

The output:

[1, 3, 5, 7, 9, 11, 13, 15, 17, 19]                                                                                                                           
[1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23]    

Answer 3

Code with list comprehenssion :-

def odd(n):
    return [num for num in range(1, n*2+1,2)]
odd(10)

Output

[1, 3, 5, 7, 9, 11, 13, 15, 17, 19]

Answer 4

range(..) can take a third parameter that is the step the amount the value increments each iteration. The last item of a list with the first n odd elements, is 2×n-1 , so we can write this as:

def odd(n):
    return list(range(1, 2*n, 2))

Answer 5

Why not just:

def odd(n):
    return list(range(1, n * 2, 2))

Answer 6

Or with numpy

import numpy as np
def odd(n):
   return np.arange(1, 2*n, 2)


odd(10) -> array([ 1,  3,  5,  7,  9, 11, 13, 15, 17, 19])
odd(12) -> array([ 1,  3,  5,  7,  9, 11, 13, 15, 17, 19, 21, 23])

Answer 7

Documentation: https://docs.scipy.org/doc/numpy-1.15.1/reference/generated/numpy.arange.html

import numpy as np

def odd(n):
   return np.arrange(1,n*2,2)

Answer 8

You can use this also:-

def odd(n):
    nums = []
    for i in range(1, n*2+1):
        if i%2==0:
            pass
        else:
            nums.append(i)
    return nums
odd(10)

Output

[1, 3, 5, 7, 9, 11, 13, 15, 17, 19]

Answer 9

def f(n):
    return[i for i in range(1,n*2,2)]

or

def E(n):
    list=[]
    list.extend(i for i in range(1,2*n,2))
    return(list)

Answer 10

With lambda AND numpy . With the help of lambda you can write function in one line AND numpy.arange is like range() but it returns an array:-

import numpy as np  # Importing numpy module
odd = lambda num: np.arange(1,num*2+1,2)   
odd(10)