{"id":5274,"date":"2020-10-02T16:59:59","date_gmt":"2020-10-02T11:29:59","guid":{"rendered":"https:\/\/www.h2kinfosys.com\/blog\/?p=5274"},"modified":"2020-10-02T17:00:01","modified_gmt":"2020-10-02T11:30:01","slug":"yield-in-python-tutorial","status":"publish","type":"post","link":"https:\/\/www.h2kinfosys.com\/blog\/yield-in-python-tutorial\/","title":{"rendered":"Yield in Python Tutorial"},"content":{"rendered":"\n

While working with a large amount of data the programmer sometimes needs to control the function\u2019s start and stop state. The Yield gives the programmer the power to execute the program the way he\/she wants rather than computing them at once. Let\u2019s take a look at an example. Suppose you have a function that prints \u201cHello World\u201d 5 times and functions that Yields \u201cHello World\u201d five times. Let\u2019s take a look at the difference between Yield and simple return for Yield in Python<\/a>.<\/p>\n\n\n\n

def normal():
print(\"Hello World\")
print(\"Hello World\")
print(\"Hello World\")
print(\"Hello World\")
print(\"Hello World\")
def yielding():
yield \"Hello World\"
yield \"Hello World\"
yield \"Hello World\"
yield \"Hello World\"
yield \"Hello World\"

normal()
print(\"Now Calling Yeilding function\")
print(yielding())<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\"Yield<\/figure>\n\n\n\n

Take a look at the above output. The normal function gives us back 5 print statements but the yielding function gives a generator.<\/p>\n\n\n\n

Now we need to loop over the generator to get the output.<\/p>\n\n\n\n

def yielding():
yield \"Hello World\"
yield \"Hello World\"
yield \"Hello World\"
yield \"Hello World\"
yield \"Hello World\"

print(\"Now Calling Yeilding function\")
output = yielding()
for i in output:
print(i)<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\"yield<\/figure>\n\n\n\n

How to read the values from the generator?<\/h2>\n\n\n\n

Let\u2019s take a look at different ways to read values from generators.<\/p>\n\n\n\n

Using : list()<\/h3>\n\n\n\n

We can use the list function to generate all the output and store it in a list.<\/p>\n\n\n\n

def even_num(x):
for i in range(x):
  if (i%3==0):
      yield i
num = even_num(20)
print(num)
print(list(num))<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\"\"<\/figure>\n\n\n\n

Using : for-loop<\/h3>\n\n\n\n

In Yield in Python, We used for loop to iterate over the generator in the first example. Let\u2019s take another example.<\/p>\n\n\n\n

def even_num(x):
for i in range(x):
  if (i%3==0):
      yield i
num = even_num(20)
print(num)
for i in num:
print(i)<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\"yield<\/figure>\n\n\n\n

Using next()<\/strong><\/h3>\n\n\n\n

There is a built-in function<\/a> next which is used to generate the next number from generator. After generating the last item it will give an error.\u00a0<\/p>\n\n\n\n

def even_num(x):
for i in range(x):
  if (i%3==0):
      yield i
num = even_num(10)
print(num)
print(next(num))
print(next(num))
print(next(num))
print(next(num))
print(next(num))<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

While working with a large amount of data the programmer sometimes needs to control the function\u2019s start and stop state. The Yield gives the programmer the power to execute the program the way he\/she wants rather than computing them at once. Let\u2019s take a look at an example. Suppose you have a function that prints […]<\/p>\n","protected":false},"author":1,"featured_media":5317,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[342],"tags":[],"class_list":["post-5274","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-python-tutorials"],"_links":{"self":[{"href":"https:\/\/www.h2kinfosys.com\/blog\/wp-json\/wp\/v2\/posts\/5274","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.h2kinfosys.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.h2kinfosys.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.h2kinfosys.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.h2kinfosys.com\/blog\/wp-json\/wp\/v2\/comments?post=5274"}],"version-history":[{"count":0,"href":"https:\/\/www.h2kinfosys.com\/blog\/wp-json\/wp\/v2\/posts\/5274\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.h2kinfosys.com\/blog\/wp-json\/wp\/v2\/media\/5317"}],"wp:attachment":[{"href":"https:\/\/www.h2kinfosys.com\/blog\/wp-json\/wp\/v2\/media?parent=5274"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.h2kinfosys.com\/blog\/wp-json\/wp\/v2\/categories?post=5274"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.h2kinfosys.com\/blog\/wp-json\/wp\/v2\/tags?post=5274"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}