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Cannot yield the right values with Python


Cannot yield the right values with Python

By : Cristian Voicu
Date : November 21 2020, 03:00 PM
will be helpful for those in need You code is fine; the usage of generator is wrong.
Just iterate it:
code :
for i in generateFalseTrueRangesAlternatively(20):
    print(i)


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Scrapy/Python: Processing values in a yield

Scrapy/Python: Processing values in a yield


By : Nagakesav
Date : March 29 2020, 07:55 AM
should help you out I am trying to write a crawler using Scrapy/Python, that reads some values from a page. , I would probably break down this part of code:
code :
yield {
    'pagetype': courses.xpath('//meta[@name="pagetype"]/@content').extract_first(),
    'pagefeatured': courses.xpath('//meta[@name="pagefeatured"]/@content').extract_first(),
    'pagedate': courses.xpath('//meta[@name="pagedate"]/@content').extract_first(),
    'pagebanner': courses.xpath('//meta[@name="pagebanner"]/@content').extract_first(),
    'pagetitle': courses.xpath('//meta[@name="pagetitle"]/@content').extract_first(),
    'pageurl': courses.xpath('//meta[@name="pageurl"]/@content').extract_first(),
    'pagedescription': courses.xpath('//meta[@name="pagedescription"]/@content').extract_first(),
    'pageid': courses.xpath('//meta[@name="pageid"]/@content').extract_first(),

    'courseatarburvale': float(courses.xpath('//meta[@name="courseatar-burvale"]/@content').extract_first('').strip() or -1),
    'courseatarrichmond': float(courses.xpath('//meta[@name="courseatar-richmond"]/@content').extract_first('').strip() or -1),
    'courseatarsomano': float(courses.xpath('//meta[@name="courseatar-somano"]/@content').extract_first('').strip() or -1),
    'courseatartucson': float(courses.xpath('//meta[@name="courseatar-tucson"]/@content').extract_first('').strip() or -1),
    'courseatarcloud': float(courses.xpath('//meta[@name="courseatar-cloud"]/@content').extract_first('').strip() or -1),
    'highestscore'; ??????
    'lowestscore'; ??????
}
item = {
    'pagetype': courses.xpath('//meta[@name="pagetype"]/@content').extract_first(),
    'pagefeatured': courses.xpath('//meta[@name="pagefeatured"]/@content').extract_first(),
    'pagedate': courses.xpath('//meta[@name="pagedate"]/@content').extract_first(),
    'pagebanner': courses.xpath('//meta[@name="pagebanner"]/@content').extract_first(),
    'pagetitle': courses.xpath('//meta[@name="pagetitle"]/@content').extract_first(),
    'pageurl': courses.xpath('//meta[@name="pageurl"]/@content').extract_first(),
    'pagedescription': courses.xpath('//meta[@name="pagedescription"]/@content').extract_first(),
    'pageid': courses.xpath('//meta[@name="pageid"]/@content').extract_first(),
}

scores = {
    'courseatarburvale': float(courses.xpath('//meta[@name="courseatar-burvale"]/@content').extract_first('').strip() or -1),
    'courseatarrichmond': float(courses.xpath('//meta[@name="courseatar-richmond"]/@content').extract_first('').strip() or -1),
    'courseatarsomano': float(courses.xpath('//meta[@name="courseatar-somano"]/@content').extract_first('').strip() or -1),
    'courseatartucson': float(courses.xpath('//meta[@name="courseatar-tucson"]/@content').extract_first('').strip() or -1),
    'courseatarcloud': float(courses.xpath('//meta[@name="courseatar-cloud"]/@content').extract_first('').strip() or -1),
}

values = sorted(x for x in scores.values() if x > 0)
scores.update({
    'highestscore': values[-1],
    'lowestscore': values[0],
})

item.update(scores)
yield item
Python yield (migrating from Ruby): How can I write a function without arguments and only with yield to do prints?

Python yield (migrating from Ruby): How can I write a function without arguments and only with yield to do prints?


By : Jimmy Tsui
Date : March 29 2020, 07:55 AM
Any of those help yield in Ruby and yield in Python are two very different things.
In Ruby yield runs a block passed as a parameter to the function.
code :
def three
  yield
  yield
  yield
end

three { puts 'hello '} # runs block (prints "hello") three times
def three(func):
  func()
  func()
  func()

three(lambda: print('hello')) # runs function (prints "hello") three times
def three():
   yield
   yield
   yield

g = three() #=> <generator object three at 0x7fa3e31cb0a0>
next(g) #=> None
next(g) #=> None
next(g) #=> None
next(g) #=> StopIteration
for _ in three():
    print('Hello')
def three
  Enumerator.new do |e|
    e.yield # or e << nil
    e.yield # or e << nil
    e.yield # or e << nil
  end
end

g = three
g.next #=> nil
g.next #=> nil
g.next #=> nil
g.next #=> StopIteration

three.each do
  puts 'Hello'
end
Python yield: return or access other values computed within a generator

Python yield: return or access other values computed within a generator


By : Massimo Caracci
Date : March 29 2020, 07:55 AM
wish helps you I would like to keep track of certain values (say count, stats) while the generator yields something else. My current approach is to pass a mutable object to the generator. Returning those values with "return" didn't seem to work. I was curious if there were other ways to do it. , How about yielding tuples consisting of the line and loc?
code :
import io

def gen_lines_of_code(file):
    loc = 0
    for line in file:
        if line.strip():
            loc += 1
            yield line, loc

file = io.StringIO("""
Lorem ipsum dolor sit amet, consectetur adipiscing elit,
sed do eiusmod tempor incididunt ut labore et dolore magna
aliqua.

Ut enim ad minim veniam, quis nostrud exercitation ullamco
laboris nisi ut aliquip ex ea commodo consequat.
""")

g = gen_lines_of_code(file)

for v, loc in g:
    print(v, end='')

try:
    print("\n\tLines of code:", loc)
except NameError:
    loc = 0
    print("\n\tLines of code:", loc)
class GenLinesOfCode:

    def __init__(self, file):
        self.file = file
        self.loc = 0

    def __iter__(self):
        for line in self.file:
            if line.strip():
                self.loc += 1
                yield line


g = GenLinesOfCode(file)

for v in g:
    print(v, end='')

print("\n\tLines of code:", g.loc)
Can a coroutine yield values in Python?

Can a coroutine yield values in Python?


By : Siddhartha
Date : March 29 2020, 07:55 AM
Does that help You are missing that when calling to send, the corrutine will go till the next yield and that one will be called, so, if you do :
code :
c=coroutine()
c.__next__()
print(c.send([1,2,3,4,5]))


for val in c:
    print(val)
def coroutine():
    print('Starting coroutine')
    value = (yield)
    yield
    for i in value:
        yield i
yield(x) vs. (yield(x)): parentheses around yield in python

yield(x) vs. (yield(x)): parentheses around yield in python


By : Juan David Cadavid Q
Date : March 29 2020, 07:55 AM
I wish this help you The yield keyword can be used in two ways: As a statement, and as an expression.
The most common use is as a statement within generator functions, usually on its own line and all. It can be used like this:
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