Question

我在.txt文件中有数据，格式为逗号分隔列表。例如：

N12345678,B,A,D,D,C,B,D,A,C,C,D,B,A,B,A,C,B,D,A,C,A,A,B,D,D
N12345678,B,A,D,D,C,B,D,A,C,C,D,B,A,B,A,C,B,D,A,C,A,A,B,D,D

我希望能够先将其拆分，然后再按行，然后使用逗号，这样我就可以处理数据并对其进行验证。我对代码中的所有行都“无效”，即使其中一些行应该有效，因为每行应该有26个字符。到目前为止，这是我的代码：

(filename+".txt").split("\n")
(filename+".txt").split(",")
with open(filename+".txt") as f:
  for line in f:
      if len(line) != 26:
          print ("invalid")
      else:
          print ("valid")

Answer 1

这段代码离工作还很远;它具有语法上有效的Python，但它并不是意味着任何合理的。

# These two lines add two strings together, returning a string
# then they split the string into pieces into a list
# because the /filename/ has no newlines in it, and probably no commas
# that changes nothing
# then the return value isn't saved anywhere, so it gets thrown away
(filename+".txt").split("\n")
(filename+".txt").split(",")

# This opens the file and reads from it line by line,
# which means "line" is a string of text for each line in the file.
with open(filename+".txt") as f:
  for line in f:

      # This checks if the line in the file is not the /number/ 26
      # since the file contains /strings/ it never will be the number 26
      if line != 26:
          print ("invalid")

      # so this is never hit
      else:
          print ("valid")

[编辑：即使在更新的代码中，line也是全文"N12345678,B,A,D..."，由于逗号，len（行）将超过26个字符。]

似乎你想要更像的东西：完全删除代码的前两行，逐行阅读文件（意味着你通常不必关心＆＃34; \ n＆＃34;在你的代码中）。然后用逗号分隔每个行。

with open(filename+".txt") as f:
  for line in f:
      line_parts = line.split(",")
      if len(line_parts) != 26:
          print ("invalid")
      else:
          print ("valid")
          # line_parts is now a list of strings
          # ["N12345678" ,"B", "A", ...]

Answer 2

我认为更简单的方法是使用csv模块。

import csv

with open("C:/text.csv") as input:
    reader = csv.reader(input)
    for row in reader:
        if len(row) == 26:
            print("Valid")
        else:
            print("Invalid")

Answer 3

据我了解你的问题，你想要这个。

with open(filename, 'r') as f:
    for line in f:
        if len(line.split(',')) !=26:
            print("Invalid")
        else:
            print("Valid")

所有这一切都是，

打开文件。
逐行阅读文件。
对于每一行，请按,
当str.split()返回一个列表时，检查列表的长度是否为26。
如果长度为26，则视为有效;否则没有。

拆分“.txt”文件

3 个答案: