pipelined generator

[akbarza]

hi
in the below code, pipelined generator has been used to sum values in a" techcrunch.csv" file and the code is in site:
https://realpython.com/introduction-to-p...generators

file_name = "techcrunch.csv"
lines = (line for line in open(file_name))
list_line = (s.rstrip().split(",") for s in lines)
cols = next(list_line)
company_dicts = (dict(zip(cols, data)) for data in list_line)
funding = (
    int(company_dict["raisedAmt"])
    for company_dict in company_dicts
    if company_dict["round"] == "a"
)
total_series_a = sum(funding)
print(f"Total series A fundraising: ${total_series_a}")

it is some ambiguous, however, at the end of the page has suggested changing this code so that in addition to sum, the average of the values should be calculated.
I thought about it, but I did not find anything.
do you have any suggestions?

second question:
(in IDLE), when I want to see the methods of a generator, I first create a generator and then I write dir(name of the generator).
it is time-consuming.
is it possible to without creating a generator, see methods related to generators? ( for string, without creating a string, I write dir(str))
also, I have this question about the result of the command"file=open(address)". namely, i want dir(f) without creating f.
I always do this time-consuming:
f= open(an address of a file)
dir(f)


thanks

[Gribouillis]

is it possible to without creating a generator, see methods related to generators?

You could add this in your module usercustomize.py

__builtins__.generator = type((x for x in ()))

Then you could use directly

dir(generator)
# or better
help(generator)

also, I have this question about the result of the command"file=open(address)". namely, i want dir(f) without creating f.

I suggest

import io
help(io.FileIO)
# or perhaps
help(io.TextIOWrapper)

[deanhystad]

I'd make funding a list.

funding = [
    int(company_dict["raisedAmt"])
    for company_dict in company_dicts
    if company_dict["round"] == "a"
]

now you can get sum(funding) and len(funding).

[akbarza]

I'd make funding a list.

funding = [
    int(company_dict["raisedAmt"])
    for company_dict in company_dicts
    if company_dict["round"] == "a"
]

now you can get sum(funding) and len(funding).

hi
the issue and problem is that we work with a large or huge file and we can not use a list. as you can see in the first code in this thread, all things were written in a generator not a list.
thanks for reply

[Gribouillis]

I can't read realpython.com because they want me to create an account, but you could do it like this

from collections import deque
from pathlib import Path

file_name = str(Path(__file__).parent/"techcrunch.csv")
lines = (line for line in open(file_name))
list_line = (s.rstrip().split(",") for s in lines)
cols = next(list_line)
company_dicts = (dict(zip(cols, data)) for data in list_line)
funding = (
    int(company_dict["raisedAmt"])
    for company_dict in company_dicts
    if company_dict["round"] == "a"
)
cumsum = 0
sums = ((cumsum := cumsum + f) for f in funding)
size, total_series_a = deque(enumerate(sums, 1), maxlen=1)[-1]
print(f"Total series A fundraising: ${total_series_a}")
print(f"Data size: {size}")
print(f"Average: {total_series_a/size}")

[DeaD_EyE]

lines = (line for line in open(file_name))
list_line = (s.rstrip().split(",") for s in lines)

Could be reduced to:

list_line = (s.rstrip().split(",") for s in open(file_name))

[akbarza]

I can't read realpython.com because they want me to create an account, but you could do it like this

from collections import deque
from pathlib import Path

file_name = str(Path(__file__).parent/"techcrunch.csv")
lines = (line for line in open(file_name))
list_line = (s.rstrip().split(",") for s in lines)
cols = next(list_line)
company_dicts = (dict(zip(cols, data)) for data in list_line)
funding = (
    int(company_dict["raisedAmt"])
    for company_dict in company_dicts
    if company_dict["round"] == "a"
)
cumsum = 0
sums = ((cumsum := cumsum + f) for f in funding)
size, total_series_a = deque(enumerate(sums, 1), maxlen=1)[-1]
print(f"Total series A fundraising: ${total_series_a}")
print(f"Data size: {size}")
print(f"Average: {total_series_a/size}")

hi and thanks for the reply
I searched the net for generator in Chrome and then I chose the realpython and I went to it(also I have realpython user and pass but I went it without using them.).
I do not understand the line:

size, total_series_a = deque(enumerate(sums, 1), maxlen=1)[-1]

what is deque and its parameters? what is [-1] at the end of it?

[akbarza]

is it possible to without creating a generator, see methods related to generators?

You could add this in your module usercustomize.py

__builtins__.generator = type((x for x in ()))

Then you could use directly

dir(generator)
# or better
help(generator)

also, I have this question about the result of the command"file=open(address)". namely, i want dir(f) without creating f.

I suggest

import io
help(io.FileIO)
# or perhaps
help(io.TextIOWrapper)

hi
what does __builtins__ ? can we use it as another object?

[deanhystad]

https://docs.python.org/3/library/builti...e-builtins

As an implementation detail, most modules have the name __builtins__ made available as part of their globals. The value of __builtins__ is normally either this module or the value of this module’s __dict__ attribute. Since this is an implementation detail, it may not be used by alternate implementations of Python.

[akbarza]

hi
is there any guide about deque?