製表符分隔的列文件中的Python搜索功能

Question

while True: 
    try: 
     OpenFile=raw_input(str("Please enter a file name: ")) 
     infile=open(OpenFile,"r") 
     contents=infile.readlines() 
     infile.close() 

     user_input = raw_input(str("Enter A=<animal> for animal search or B=<where lives?> for place of living search: \n")) 
     if user_input.startswith("A="): 
      def find_animal(user_input,column): 
       return next(("\t".join(line) for line in contents 
          if line[column-1]==user_input),None) 
      find_animal(user_input[1:]) 
      print str((find_animal(user_input[1:], "WHO?"))) #"Who?" is the name of the first column. 

     else: 
      print "Unknown option!" 


    except IOError: 
     print "File with this name does not exist!" 

1.輸入動物名稱。

2.程序在第一列中搜索具有此特定名稱的行。

3.Program在第一列中打印具有此名稱的行。

我的功能似乎無法在這裏正常工作。你能幫我找到錯誤嗎？謝謝！

編輯

 def ask_for_filename(): 
     filename=str(raw_input("Please enter file name: ")) 
     return filename 

     def read_data(filename): 
     contents=open(filename,"r") 
     data=contents.read() 
     return data 

     def column_matches(line, substring, which_column): 
     for line in data: 
      if column_matches(line, substring, 0): 
       print line 

Answer 1

的代碼大塊難以閱讀和調試，嘗試拆分代碼成更小的功能，例如像這樣：

def ask_for_filename(): 
    #left as an exercise 
    return filename 

def read_data(filename): 
    #left as an exercise 
    return data 

def column_matches(line, substring, which_column): 
    #left as an exercise 

def show_by_name(name, data): 
    for line in data: 
     if column_matches(line, name, 0): 
      print line 

def do_search(data): 
    propmt = "Enter A=<animal> for animal search or B=<where lives?> for place of living search: \n" 
    user_input = raw_input(prompt) 
    if user_input.startswith('A='): 
     show_by_name(user_input[2:], data) 

# main program 

filename = ask_for_filename() 
data = read_data(filename) 
while True: 
    do_search(data) 

測試和調試這些功能分開直到你確定它們正常工作。然後編寫並測試主程序。

column_matches()應該返回true，如果line中的某列（which_column）等於substring。例如，column_matches("foo\tbar\tbaz", "bar", 1)是True。爲了實現這一目標

• 由分隔符分割線 - 這給了我們值的列表
• 獲取列表
• 與substing比較它的第n個元素
• 返回true，如果他們是相等的，否則爲false

全部放在一起：

def column_matches(line, substring, which_column): 
    delimiter = '\t' 
    columns = line.split(delimiter) 
    value = columns[which_column] 
    if value == substring: 
     return True 
    else: 
     return False 

或以更簡潔和「pythonic」形式：

def column_matches(line, substring, which_column): 
    return line.split('\t')[which_column] == substring