当我可以1个功能但3个功能同时工作时，这个脚本如何工作？

Question

此代码是从https://www.youtube.com/watch?v=XhXOsgdC9h0

复制的

import requests
from bs4 import BeautifulSoup
import operator

#get all the words in the website
def all_words(url,):
    word_list = []
    source_code = requests.get(url).text #connect to url
    soup = BeautifulSoup(source_code, "html.parser")
    for before_text in soup.find_all("a", {"class": "result-title"}):
        content = before_text.string
        words = content.lower().split() #trun all words into lower case and split
        for each_word in words:
            word_list.append(each_word)
    clean_up_list(word_list)

#remove all the symbols in each word
def clean_up_list(word_list):
    clean_word_list = []
    for word in word_list:
        symbols = "!@#$%^&*()_+[]\"\-;',./<>?"
        for  i in range(0, len(symbols)):
            word = word.replace(symbols[i], "") #replace all symbols with blank space
        if len(word) > 0: #only word with length > 0 can be added
            print(word)
            clean_word_list.append(word)
    create_dictionary(clean_word_list)

#count the frequency of each word in the list
def create_dictionary(clean_word_list):
    word_count = {}
    for word in clean_word_list:
        if word in word_count:
            word_count[word] += 1
        else:
            word_count[word] = 1
    for key, value in sorted(word_count.items(), key = operator.itemgetter(1)): #sort the item from the largest value
        print (key, value)

all_words("https://cnj.craigslist.org/search/sys")

因此代码只是试图计算网站中每个单词的频率。我不明白我只调用函数all_words，但实际上它运行代码中的所有函数。它是如何发生的？

谢谢！

Answer 1

您在函数末尾调用all_words("https://cnj.craigslist.org/search/sys")的函数末尾调用clean_up_list(word_list) create_dictionary(clean_word_list)。

所以你的3个函数被调用。