Question

我正在编写一个程序来读取邮政编码的文本文件，当输入正确的数字时，该文件应打印邮政编码的位置。但是，我在编写错误消息时遇到问题。我尝试了各种方法，无法获取打印错误信息，这就是我所拥有的：

Abbeville         AL 36310
Abernant          AL 35440
Acmar             AL 35004
Adamsville        AL 35005
Addison           AL 35540
Adger             AL 35006
Akron             AL 35441
Alabaster         AL 35007

一些示例邮政编码：

DayOfWeek

Answer 1

我不确定enterFile的重要性。如果从异常中删除enterFile，则应该看到错误消息，因为它似乎没有定义。

Answer 2

我相信您需要在此计划中分两个阶段：

阅读zipcodes.txt并构建您的目录。
询问用户邮政编码;打印相应的位置。

您当前的＆＃34;积极的＆＃34;逻辑是

else:
    for line in myFile:
       words = line.split()       # Get the next line from zipcodes.txt
       if words[2] == ask:        # If this ZIP code matches the input,
          zipcode = words[0:2]    # assign the line's three fields as a list.

# Variable zipcode now contains a single line's data, all three fields.
#   You threw away the empty dictionary.

for value in zipcode:    # Print all three fields of the one matching line.
    print value,

需要逻辑（在我看来）

# Part 1: read in the ZIP code file
# For each line of the file:
#    Split the line into location and ZIP_code
#    zipcode[ZIP_code] = location

# Part 2: match a location to the user's given ZIP code
# Input the user's ZIP code, "ask"
# print zipcode[ask]

这个pseduo代码是否会让您转向解决方案？

Answer 3

从一开始：

try:
    myFile=open("zipcodes.txt") 
except: 
    print "File can't be opened:", myFile # if open fail then myFile will be undefined.
    exit()

zipcode = dict() # you creating dict, but you never add something into it.

line = myFile.readline() # this will read only first line of file, not each

ask = raw_input("Enter a zip code: ") 

if ask not in line:  
    # it will print not found for any zipcode except zipcode in first line
    print "Not Found."
else:
    # because you already read 1 line of myFile
    # "for line in " will go from second line to end of file

    for line in myFile: # 1 line already readed. Continue reading from second 
       words = line.split() 
       if words[2] == ask: # If you don't have duplicate of first line this will never be True
          zipcode = words[0:2]

# So here zipcode is an empty dict. Because even if "ask is in line"
# You never find it because you don't check line 
# where the ask is (the first line of file).
for value in zipcode:
    # print never executed becouse zipcode is empty
    print value,

搜索文件以获取输入Python

3 个答案: