Why is being indent's wrong causes wrong function? - python-3.x

Question

I cannot understand why this error happen.
First,I wrote
import urllib.request
from bs4 import BeautifulSoup
import time
import os
def download_image(url,name):
path = "./scrape_image/"
imagename = str(name) + ".jpg"
if not os.path.exists(path):
os.makedirs(path)
print(path)
urllib.request.urlretrieve(url,path+imagename)
url = "https://api.XXXkeyword=YYY&limit=1000"
response = urllib.request.urlopen(url)
rss = response.read().decode("utf-8")
soup = BeautifulSoup(rss, "xml")
name=0
for s in soup.find_all("photo"):
url = s.find_all("image_url")[0].string
name+=1
download_image(url, name)
by running this code,I can get 1 image from the API.But originally the right code can get 1000 images from the API.I fixed indents in the first code, so my code is like
import urllib.request
from bs4 import BeautifulSoup
import time
import os
def download_image(url,name):
path = "./image/"
imagename = str(name) + ".jpg"
if not os.path.exists(path):
os.makedirs(path)
print(path)
urllib.request.urlretrieve(url, path+imagename)
time.sleep(1)
url = "https://api.XXXkeyword=YYY&limit=1000"
response = urllib.request.urlopen(url)
rss = response.read().decode("utf-8")
soup = BeautifulSoup(rss, "xml")
name = 0
for s in soup.find_all("photo"):
url = s.find_all("image_url")[0].string
name+=1
download_image(url,name)
At last,I can get 1000 images from the API. But I cannot understand why I can do so by fixing the indent.Please give me some explanations.

Answer 1

Because in the first example you're only getting the image if your condition passes:
if not os.path.exists(path):
And that condition will only pass once because you immediately create the path:
os.makedirs(path)
For every other iteration of the loop, the condition is false. So the code within the conditional block doesn't execute.
Basically, an if block only executes if the condition is true. When you move your code out of the if block, it always executes regardless of the condition.