将数据写入 csv 文件 Python

Question

我的数据如下所示

['[\'Patient, A\', \'G\', \'P\', \'RNA\']']

无论括号、引号和反斜杠如何，我都想用“,”分隔数据并写入如下所示的 CSV 文件

Patient,A,G,P,RNA

提及分隔符 = ',' 没有任何帮助。然后输出文件看起来像

['Patient, A','G','P','RNA']

全部在一个单元格中。我想将它们分成多列。我该怎么做？

编辑 - 提到 quotechar='|' 将它们分成不同的单元格，但现在看起来像

|['Patient, A','G','P','RNA']|

编辑-

out_file_handle = csv.writer(out_file, quotechar='|', lineterminator='\n', delimiter = ",")
data = ''.join(mydict.get(word.lower(), word) for word in re.split('(\W+)', transposed))
data = [data,]
out_file_handle.writerow(data)

转置：

['Patient, A','G','P','RNA']

数据：

['[\'Patient, A\', \'G\', \'P\', \'RNA\']']

而且它有多行，上面是整个数据中的一行。

Answer 1

您首先需要将此数据读入 Python 数组，方法是将字符串作为 CSV 文件在内存中处理：

from StringIO import StringIO
import csv
data = ['[\'Patient, A\', \'G\', \'P\', \'RNA\']']
clean_data = list(csv.reader( StringIO(data[0]) ))

但是输出仍然是单个字符串，因为它甚至不是格式正确的 CSV！在这种情况下，最好的办法可能是过滤掉所有这些垃圾字符？

import re
clean_data = re.sub("[\[\]']","",data[0])

现在 data[0] 是 'Patient, A, G, P, RNA'，这是一个干净的 CSV，您可以直接写入文件。

Answer 2

如果您要做的是以['[\'Patient, A\', \'G\', \'P\', \'RNA\']'] 的形式将数据写入文件，其中您有这些字符串的数组，那么这确实是一个分为两部分的问题。

首先是如何将数据分离成正确的格式，其次是写入文件。

如果这是您的数据的形式，对于每一行，那么这样的东西应该可以工作（将其转换为正确的格式）：

data = ['[\'Patient, A\', \'G\', \'P\', \'RNA\']', ...]
newData = [entry.replace("\'", "")[1:-1].split(",") for entry in data]

这将为您提供以下形式的数据：

[["Patient", "A", "G", "P", "RNA"], ...]

然后您可以按照其他答案中的建议将其写入文件；

with open('new.csv', 'wb') as write_file:
  file_writer = csv.writer(write_file)
  for dataEntry in range(newData ):
    file_writer.writerow(dataEntry)

如果您实际上并不关心使用这一轮中的数据，而只是想清理它，那么您可以直接执行data.replace("\'", "")[1:-1]，然后将这些字符串写入文件。

[1:-1] 位仅用于删除前导方括号和尾随方括号。

Answer 3

Python 有一个 CSV 写入器。从

开始

import csv

然后尝试这样的事情

with open('new.csv', 'wb') as write_file:
    file_writer = csv.writer(write_file)
    for i in range(data):
        file_writer.writerow([x for x in data[i]])

编辑：

在写入数据之前，您可能需要先处理一下数据，因为它看起来像是一个字符串，而不是一个列表。尝试使用 split() 函数

list = data.split()

Answer 4

"""
                             SAVING DATA INTO CSV FORMAT
    * This format is used for many purposes, mainly for deep learning.
    * This type of file can be used to view data in MS Excel or any similar 
      Application
"""
# == Imports ===================================================================

import csv
import sys

# == Initialisation Function ===================================================

def initialise_csvlog(filename, fields):
    """
    Initilisation this function before using the Inserction function

    * This Function checks the data before adding new one in order to maintain
      perfect mechanisum of insertion
    * It check the file if not exists then it creates a new one
    * if it exists then it proceeds with getting fields

    Parameters
    ----------
    filename : String
        Filename along with directory which need to be created
    Fields : List
        Colomns That need to be initialised

    """
    try :
        with open(filename,'r') as csvfile:
            csvreader = csv.reader(csvfile)
            fields = csvreader.next()
            print("Data Already Exists")
            sys.exit("Please Create a new empty file")
            # print fields  
    except :
        with open(filename,'w') as csvfile:

            csvwriter = csv.writer(csvfile)
            csvwriter.writerow(fields)

# == Data Insertion Function ===================================================

def write_data_csv(filename, row_data):
    """
    This Function save the Row Data into the CSV Created
    * This adds the row data that is Double Listed

    Parameters
    ----------
    filename : String
        Filename along with directory which need to be created
    row_data : List
        Double Listed consisting of row data and column elements in a list  
    """
    with open(filename,'a') as csvfile:

        csvwriter = csv.writer(csvfile)
        csvwriter.writerows(row_data)

if __name__ == '__main__':
    """
    This function is used to test the Feature Run it independently

    NOTE: DATA IN row_data MUST BE IN THE FOLLOWING DOUBLE LISTED AS SHOWN
    """
    filename = "TestCSV.csv"
    fields = ["sno","Name","Work","Department"]
    #Init
    initialise_csvlog(filename,fields)
    #Add Data
    row_data = [["1","Jhon","Coder","Pythonic"]]
    write_data_csv(filename,row_data)

# == END =======================================================================

阅读模块，您可以开始使用 CSV 并在 Excel 或任何类似应用程序中查看数据（在 libreoffice 中计算）

注意：请记住将要双重列出的数据列表如__main__ 函数（row_data）所示