def key_of_min(d):
  return min(d, key = d.get)

key_of_min({'a':4, 'b':0, 'c':13}) # b

filename = "data.txt"
data = "Hello, World!"

with open(filename, "a") as file:
    file.write(data)

list_1 = [1,2,3,4,5,6,7,8,9]
cubed = map(lambda x: pow(x,3), list_1)
print(list(cubed))

#Results
#[1, 8, 27, 64, 125, 216, 343, 512, 729]

# Python Program to calculate the square root

num = float(input('Enter a number: '))

num_sqrt = num ** 0.5
print('The square root of %0.3f is %0.3f'%(num ,num_sqrt))

# Python program for implementation of Bubble Sort

def bubbleSort(arr):
	n = len(arr)

	# Traverse through all array elements
	for i in range(n-1):
	# range(n) also work but outer loop will repeat one time more than needed.

		# Last i elements are already in place
		for j in range(0, n-i-1):

			# traverse the array from 0 to n-i-1
			# Swap if the element found is greater
			# than the next element
			if arr[j] > arr[j+1] :
				arr[j], arr[j+1] = arr[j+1], arr[j]

# Driver code to test above
arr = [64, 34, 25, 12, 22, 11, 90]

bubbleSort(arr)

print ("Sorted array is:")
for i in range(len(arr)):
	print ("%d" %arr[i]),

primes=[]
products=[]

def prime(num):
    if num > 1:
        for i in range(2,num):
            if (num % i) == 0:
                return False
        else:
            primes.append(num)
            return True

for n in range(30,1000):
    if len(primes) >= 20:
        break;
    else:
        prime(n)

for previous, current in zip(primes[::2], primes[1::2]):
    products.append(previous * current)
    
print (products)