Using tkinter to input into a variable, to be called

Here is a diminutive example based on your code; it allows to use the entry field to capture the value of the wiki page to visit, and prints it on the console.
You can then use this url to proceed with your scraping.

from tkinter import *def m_quit():    global wiki_url    wiki_url += e1.get() + '/'    print('quitting')    master.destroy()wiki_url = 'http://en.wikipedia.org/wiki/'    master = Tk()Label(master, text="Wikipedia URL").grid(row=0)e1 = Entry(master)e1.grid(row=0, column=1)Button(master, text='Scrape', command=m_quit).grid(row=3, column=0, sticky=W, pady=4)mainloop()print(wiki_url)

The code was almost correct. A few modifications were enough. Hope this helps. Please comment if you need any further clarifications.

    import requests    from bs4 import BeautifulSoup    import re    from tkinter import *    # you can declare selectWikiPage and master to be global and then avoid passing them around    # begin tkinter gui    def show_entry_fields():        print("Wikipedia URL: %s" % (e1.get()))        e1.delete(0, END)    #utility which selects all the text from start to end in widget    def select_all(event=None):        event.widget.select_range(0, 'end')        return 'break'    #the code is same, just obtained the URL from the widget using get()    def custom_scrape(e1, master):        session = requests.Session()        # selectWikiPage = input("Please enter the Wikipedia page you wish to scrape from")        selectWikiPage = e1.get()        if "wikipedia" in selectWikiPage:            html = session.post(selectWikiPage)            bsObj = BeautifulSoup(html.text, "html.parser")            findReferences = bsObj.find('ol', {'class': 'references'})  # isolate refereces section of page            href = BeautifulSoup(str(findReferences), "html.parser")            links = [a["href"] for a in href.find_all("a", href=True)]            for link in links:                print("Link: " + link)        else:            print("Error: Please enter a valid Wikipedia URL")        master.quit()    master = Tk()    Label(master, text="Wikipedia URL").grid(row=0)    e1 = Entry(master)    #bind ctrl+a for selecting all the contents of Entry widget    e1.bind('<Control-a>', select_all)    e1.insert(10, "Enter a wikipedia URL")    e1.grid(row=0, column=1)    #here, command attribute takes a lambda which itself doesnot take any args,    #but in turn calls another function which accepts    #arguments    #Refer to: https://stackoverflow.com/questions/22723039/python-tkinter-passing-values-with-a-button for details    Button(master, text='Scrape', command=lambda: custom_scrape(e1, master)).grid(row=3, column=0, sticky=W, pady=4)    mainloop()