從Python中輸入的值中提取電子郵件

Question

我的目標是：我需要讓用戶輸入電子郵件的數量，然後啓動一個for循環來註冊輸入的電子郵件。然後，這些電子郵件將根據'@ professor.com'和'@ student.com'分類。這將在列表中作爲追加計數。以下是我已經嘗試過

email_count = int(input('how many emails you want')) 
student_email_count = 0 
professor_email_count = 0 
student_email = '@student.com' 
professor_email = '@professor.com' 

for i in range(email_count): 
    email_list = str(input('Enter the emails') 
    if email_list.index(student_email): 
     student_email_count = student_email_count + 1 
    elif email_list.index(professor_email): 
     professor_email_count = professor_email_count + 1 

有人可以幫助縮短這個，並寫下專業解釋以供進一步參考？在這裏，追加部分丟失了。那裏有人能通過一些光線嗎？

謝謝

Answer 1

prof_email_count, student_email_count = 0, 0 

for i in range(int(input("Email count # "))): 
    email = input("Email %s # " % (i+1)) 

    if email.endswith("@student.com"): # str.endswith(s) checks whether `str` ends with s, returns boolean 
     student_email_count += 1 
    elif email.endswith("@professor.com"): 
     prof_email_count += 1 

是您的代碼的（有點）縮短移交會是什麼樣子。主要區別在於我使用str.endswith(...)而不是str.index(...)，我也刪除了email_count,student_email和professor_email變量，這些變量在上下文中的其他任何地方都沒有使用。

編輯：

要回答的可擴展性的評論，你可以實現一個系統，像這樣：

domains = { 
    "student.com": 0, 
    "professor.com": 0, 
    "assistant.com": 0 
} 

for i in range(int(input("Email count # "))): 
    email = input("Email %s # " % (i+1)) 

    try: 
     domain = email.split('@')[1] 
    except IndexError: 
     print("No/invalid domain passed") 
     continue 

    if domain not in domains: 
     print("Domain: %s, invalid." % domain) 
     continue 

    domains[domain] += 1 

它允許進一步的擴展性，你可以添加更多的域到domains詞典，訪問計數每domains[<domain>]

Answer 2

看來你的迭代每次只接受一封郵件;並執行email_count次。你可以使用這個簡單的代碼來統計學生和教授：

st = '@student.com' 
prof = '@professor.com' 

for i in range(email_count): 
    email = str(input('Enter the email')) 
    if st in email: 
     student_email_count += 1 
    elif prof in email: 
     professor_email_count += 1 
    else: 
     print('invalid email domain') 

如果您正在使用Python 2.7，你應該改變輸入的raw_input。

---

這是您的代碼的可擴展版本，使用defaultdict來支持無限域。

email_count = int(input('how many emails you want')) 
student_email_count = 0 
professor_email_count = 0 

from collections import defaultdict 
domains = defaultdict(int) 

for i in range(email_count): 
    email = str(raw_input('Enter the email\n')) 
    try: 
     email_part = email.split('@')[1] 
    except IndexError: 
     print('invalid email syntax') 
    else: 
     domains[email_part] += 1