lambda function not printing values instead printing object value

Question

I have a script that emails me links to me.

The problem is the links arent included, instead I get:

<function <lambda> at 0x7f75b5fb4a60>

My script looks like:

from bs4 import BeautifulSoup
import re
import requests

ex_webdev_js_by_city = [
'http://boston.website.org/search/web',
]

ex_web_j_keywords = [['one'],['coool', 'person']]
ex_web_j_keywords = sum(ex_web_j_keywords, [])

ex_js = []

for webdev_j_for_a_city in ex_webdev_js_by_city:
    webdev_j = requests.get(webdev_j_for_a_city)
    soup = BeautifulSoup(webdev_j.text, "lxml")
    for j_keyword in ex_web_j_keywords:
        for a in soup.find_all('a', class_="result-title hdrlnk", text=re.compile(j_keyword,re.IGNORECASE)):
            #print(a.get('href'))
            ex_js.append(a.get('href'))

if ex_js:
   #email them to myself!
   import smtplib, socket
   TO = 'myemail@gmail.com'

   try:
       server = smtplib.SMTP('smtp.gmail.com', 587)
       server.starttls()
       TEXT = lambda: print(('Latest js from site:\n\n{}'*len(ex_js)).format(*ex_js))
       #Gmail Sign In
       gmail_sender = 'myemail'
       gmail_passwd = 'mypass'
       server.login(gmail_sender, gmail_passwd)
       msg = str(TEXT)
       server.sendmail(gmail_sender, gmail_sender, msg)
       print('Sent you some links!')
       server.quit()
   except socket.error as e:
       print ('error sending mail, error was {}'.format(e))

The error is occuring on this line (I believe):

lambda: print(('Latest js from site:\n\n{}'*len(ex_js)).format(*ex_js))

It appears its printing out the object details in the email to me, and not the value .

Thus, what am i possibly doing wrong here?

Answer 1

I don't know why you use print or lambda anyway. If you simply wrote:

msg = ('Latest js from site:\n\n{}'*len(ex_js)).format(*ex_js)

and drop the:

msg = str(TEXT)

it should probably work.

So the try block should read:

server = smtplib.SMTP('smtp.gmail.com', 587)
server.starttls()

#Gmail Sign In
gmail_sender = 'myemail'
gmail_passwd = 'mypass'
server.login(gmail_sender, gmail_passwd)
 !!commented out!! (only to make it explicit)
server.sendmail(gmail_sender, gmail_sender, msg)
print('Sent you some links!')
server.quit()

---

I think however that you do not really understand what lambda and print are supposed to do. print is used to write data to the standard output channel , but you want to write it into an email, so you do not need to print it locally, you need somehow to store your message in memory .

Finally lambda:... is used to create an anonymous function , if you do not feed it any arguments, its usage is usually to postpone execution (for instance to achieve laziness). But here you actually need the message , so again no need to use this construct.

Answer 2

When you say

TEXT = lambda: print(('Latest js from site:\n\n{}'*len(ex_js)).format(*ex_js))

Yo are simply creating lambda function , it is not executed yet . In order to execute you need to specifically invoke it by calling TEXT()

In order to fix your problem change to

TEXT = lambda: ('Latest js from site:\n\n{}'*len(ex_js)).format(*ex_js)

And msg = str(TEXT())