Python：把第一個字符沒有列表

Question

我的代碼是關於用每個單詞/數字的第一個字符/數字作爲一個句子/短語中的一個字符來創建一個密碼，並且就像這樣打印它。

示例：停下來嗅到350朵「玫瑰花」。 - > Sast3r。 （忽略使用用r 報價）

這將是非常容易使用列表，但你不能在這個分配使用它們我的代碼。所以，我不知道要什麼有什麼我迄今所做的後現在要做的

功能：

def create_password(phrase): 
q = "'" # quotations 
dq = '"' # double quotes 

password = phrase[0] 

for i in phrase: 
    x = phrase.find(" ") 
    if i.isalnum: 
     password += phrase[x + 1] 
    elif x == q or x == dq: 
     password += phrase[x + 2] 

return password 

主營：

# Imports 
from credentials import create_password 

# Inputs 
phrase = str(input("Enter a sentence or phrase: ")) 

# Outputs 
password = create_password(phrase) 
print(password) 

Answer 1

我認爲遍歷整個短語更簡單，不用擔心在空間上分裂。請記住你是否剛剛看過一個空間。你只想在看到空格後添加角色。

def create_password(phrase): 
    q = "'" # quotations 
    dq = '"' # double quotes 

    #Initialize the password to be an empty string 
    password = "" 

    #We are at the start of a new word (want to add first index to password) 
    new_word = True 

    #Walk through every character in the phrase 
    for char in phrase: 

     #We only want to add char to password if the following is all true: 
     #(1) It's a letter or number 
     #(2) It's at the start of a new word 
     #(3) It's not a single quote 
     #(4) It's not a double quote 
     if char.isalnum and new_word: 
      if char != q and char != dq: 
       password += char 
       new_word = False #<-- After adding char, we are not at a new word 

     #If we see a space then we are going to be at a new word 
     elif char == " ": 
      new_word = True 

    return password 

p = create_password('Stop and smell the 350 "roses"') 
print(p) 

輸出：

Sast3r 

Answer 2

嘗試採取的第一個字符字符串中，和然後是每個跟隨空間的角色。看起來你有正確的想法。

Answer 3

你絕對走在正確的軌道上！使用str.find()方法絕對是最好的選擇！

但是，您需要了解str.find()方法的作用。看看簽名：

str.find(sub [,start [,end) -> int 

    # sub -> character to find 
    # start -> where the function should start looking in the string 
    # end -> where the function should stop looking 

    # Returns a number, which is the place it found the character. 
    # If it didn't find anything, then return -1. 

不告訴函數從哪裏開始，它總是會在字符串中找到第一個出現的字符。它不會知道你正在瀏覽字符串的每個字符。

因此，讓我們改變了一點點：

for char_index in xrange(len(phrase)): 
    # Tell the method to look after char_index: we've already looked before this! 
    x = phrase.find(' ', char_index) index 

    if phrase[x+1].isalnum(): # It's a function, notice the brackets? 
     password += phrase[x + 1] 
    elif phrase[x+2] == q or phrase[x+2] == dq: 
     password += phrase[x + 2] 

但願，這應該得到您想要的密碼。

Answer 4

給予優先使用內置的功能，例如，每次找到的空間位置，那麼爲什麼不直接按照空間瀉函數，讓字符串直接到字符列表中，每個元素都是一個字，然後刪除列表中的每個元素。

def create_password(phrase): 
    password = '' 
    phrase_list = phrase.split(' ') 
    print (phrase_list) 

    for i in phrase_list: 
     print (i[0]) 
     password += i[0] 
    return password 

if __name__ == '__main__': 
    # Inputs 
    phrase = str(input("Enter a sentence or phrase: ")) 

    # Outputs 
    password = create_password(phrase) 
    print(password)