检查字符串是否为CSV [英] Check whether string is in CSV

问题描述

我想搜索CSV文件并打印 True 或 False ，具体取决于我是否找到字符串。但是，我遇到的问题，它会返回一个假阳性，如果它发现字符串嵌入在一个较大的文本字符串。例如：如果string是 foo 和术语 foobar ，它将返回 True $ c>在CSV文件中。我需要能够返回完全匹配。

I want to search a CSV file and print either True or False, depending on whether or not I found the string. However, I'm running into the problem whereby it will return a false positive if it finds the string embedded in a larger string of text. E.g.: It will return True if string is foo and the term foobar is in the CSV file. I need to be able to return exact matches.

username = input()

if username in open('Users.csv').read():
    print("True")
else:
    print("False")

我看过使用 mmap ， re 和 csv 模块函数，但我没有任何地方。

I've looked at using mmap, re and csv module functions, but I haven't got anywhere with them.

另一种方法：

import re
import csv

username = input()

with open('Users.csv', 'rt') as f:
     reader = csv.reader(f)
     for row in reader:
          re.search(r'\bNOTSUREHERE\b', username)

推荐答案

当使用 csv 模块查看csv文件时，它将以列的列表的形式返回每一行。所以如果你想查找你的字符串，你应该修改你的代码如下：

when you look inside a csv file using the csv module, it will return each row as a list of columns. So if you want to lookup your string, you should modify your code as such:

import csv

username = input()

with open('Users.csv', 'rt') as f:
     reader = csv.reader(f, delimiter=',') # good point by @paco
     for row in reader:
          for field in row:
              if field == username:
                  print "is in file"

，但由于它是一个csv文件，您可能希望用户名位于给定的列：

but as it is a csv file, you might expect the username to be at a given column:

with open('Users.csv', 'rt') as f:
     reader = csv.reader(f, delimiter=',')
     for row in reader:
          if username == row[2]: # if the username shall be on column 3 (-> index 2)
              print "is in file"

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