一个 function ，它接受一个整数列表并在屏幕上打印一个长度为 integer 的星号

Question

first of all, hello to everyone, I'm a first timer in here. anyways. I had this problem and I dont have a real direction.:. I tried this:

def MyStars(inputList):
l = len(inputList)
ret = []
for x in inputList:
  ret.append("* ")
print(ret)

but then I realised that the output is a string of * which last the number of integers I have in the original List... the outcome is:

['* ', '* ', '* ']

while I want it to be for the list [3,9,7] for example:

*** ********* *******

can someone help? tnx

Answer 1

I would not use append but a list comprehension with string multiplication:

def MyStars(inputList):
    print(' '.join(['*'* i for i in inputList]))
    
MyStars([3, 9, 7])

output: *** ********* *******

To fix your code, you would need 2 loops, one to iterate over the numbers, and one to append your characters, then join your lists:

def MyStars(inputList):
    l = len(inputList)
    for x in inputList:
        ret = []
        for i in range(x):
            ret.append('*')
        print(''.join(ret), end=' ')
    
MyStars([3, 9, 7])

NB. note that this version gives a trailing space.

Answer 2

try this code.

What happened with your code is that you were close to the answer, but you needed to use the range function and loop through x to add the correct number of stars to your list.

def MyStars(inputList):
   l = len(inputList)
   ret = []
   for x in inputList:
       for i in range(x):
          ret.append("*")
       ret.append(" ")
   for a in ret:
       print(a)

Answer 3

If to print is all you want to do, you can just

print(*("*" * n for n in input_list))

which for input_list = [3, 9, 7] prints *** ********* *******

• <s: str> * <n: int> multiplies string s n times eg "xYZ" * 3 will result in "xYZxYZxYZ" (in this case "*" * 3 will be "***" )
• ("*" * n for n in input_list) creates a collection of "*" * n -s for each n in input_list (this creates a generator that can be iterated only once, if you want to iterate the collection more than once, you can create eg a list( [...] ) instead)
• print(*<iterable>) prints each item of the iterable and separates them with sep (that is by default a space, which happens to be what you want, you can pass sep as a print param, eg print(*<iterable>, sep="\n")

An example of fixing your solution (I also adjusted naming to follow python conventions):

def my_stars(input_list):
    stars_strings = []
    for x in input_list:
        stars_strings.append("*" * x)
    ret = " ".join(stars_strings)
    print(ret)