Python从文件中提取和排序数据

我试图以以下格式从大型CSV文件中提取数据，假设“x”是文本或整数形式的数据。每个分组都有一个唯一的id，但每个分组或颜色的行数并不总是相同的。数据与颜色之间用逗号分隔

id, x
red, x
green, x
blue, x 
black, x

id, x
yellow, x
green, 
blue, x 
black, x

id, x
red, x
green, x
blue, x
black, x

id, x
red, x
green, x
blue, x

id, x
red, x
green, x
blue, x 
black, x

我想以列格式重新排列数据。ID应该是第一列，任何数据都用逗号分隔。我的目标是让它阅读行中的第一个单词，并将其放在适当的列中

line 0 - ID - red - green - blue - yellow - black
line 1 - x, x, x,  , x,
line 2 -  , x, x, x, x,
line 3 - x, x, x,  , x,
line 4 - x, x, x,  ,  ,
line 5 - x, x, x,  , x,

这就是我想要的

readfile = open("db-short.txt", "r")
datafilelines = readfile.readlines()

writefile = open("sample.csv", "w")

temp_data_list = ["",]*7
td_index = 0

for line_with_return in datafilelines:
    line = line_with_return.replace('\n','') 
    if not line == '':
        if not (line.startswith("ID") or 
                line.startswith("RED") or
                line.startswith("GREEN") or
                line.startswith("BLUE") or
                line.startswith("YELLOW") or
                line.startswith("BLACK") ):
            temp_data_list[td_index] = line
            td_index += 1

            temp_data_list[6] = line
        if (line.startswith("BLACK") or line.startswith("BLACK")):
            temp_data_list[5] = line
        if (line.startswith("YELLOW") or line.startswith("YELLOW")):
            temp_data_list[4] = line
        if (line.startswith("BLUE") or line.startswith("BLUE")):
            temp_data_list[3] = line
        if (line.startswith("GREEN") or line.startswith("GREEN")):
            temp_data_list[2] = line
        if (line.startswith("RED") or line.startswith("RED")):
            temp_data_list[1] = line
        if (line.startswith("ID") or line.find("ID") > 0):
            temp_data_list[0] = line
    if line == '':
        temp_data_str = ""
        for temp_data in temp_data_list:
            temp_data_str += temp_data + ","
        temp_data_str = temp_data_str[0:-1] + "\n"
        writefile.write(temp_data_str)

        temp_data_list = ["",]*7 
        td_index = 0

if temp_data_list[0]:
    temp_data_str = ""
    for temp_data in temp_data_list:
        temp_data_str += temp_data + ","
    temp_data_str = temp_data_str[0:-1] + "\n"
    writefile.write(temp_data_str)
readfile.close()
writefile.close()

这假设Python<2.7（因此不会利用使用打开一个

的多个文件，使用内置的
写头程序
写入头文件等。请注意，为了使其正常工作，我删除了CSV中逗号之间的空格。正如@JamesHenstridge所提到的，它肯定值得在<代码>csv

模块，使其更有意义

import csv

with open('testfile', 'rb') as f:
  with open('outcsv.csv', 'wb') as o:
    # Specify your field names
    fieldnames = ('id', 'red', 'green', 'blue', 'yellow', 'black')

    # Here we create a DictWriter, since your data is suited for one
    writer = csv.DictWriter(o, fieldnames=fieldnames)

    # Write the header row
    writer.writerow(dict((h, h) for h in fieldnames))

    # General idea here is to build a row until we hit a blank line,
    # at which point we write our current row and continue
    new_row = {}
    for line in f.readlines():
      # This will split the line on a comma/space combo and then
      # Strip off any commas/spaces that end a word
      row = [x.strip(', ') for x in line.strip().split(', ')]
      if not row[0]:
        writer.writerow(new_row)
        new_row = {}
      else:
        # Here we write a blank string if there is no corresponding value;
        # otherwise, write the value
        new_row[row[0]] = '' if len(row) == 1 else row[1].strip()

    # Check new_row - if not blank, it hasn't been written (so write)
    if new_row:
      writer.writerow(new_row)

使用上面的数据（加上一些随机的逗号分隔数字），可以这样写：

id,red,green,blue,yellow,black
x,"2,8","2,4",x,,x
x,,,"4,3",x,x
x,x,x,x,,x
x,x,x,x,,
x,x,x,x,,x

---

到目前为止，您尝试了什么？标准库

csv

模块可能是一个很好的开始。我知道您说过您想要一个python解决方案，但您考虑过R吗？它是为这些任务而构建的。我会承认我是编程新手，我尝试过使用它……但我一直遇到这个错误。Indexer:list assignment index超出范围现在我了解到这是因为数据的格式，我将看一看你在

for

语句中缺少

if

语句的开头吗？@JamesHenstridge Ha是的，不知道怎么没有粘贴。会在一点后更新，谢谢你指出。te之间有随机空格xt和逗号，有没有办法让它检测到空格并删除它们？@thedave是的，我不适合在您显示数据时更改数据。我将添加一个更新来解决这个问题。修复方法是

去除字符串中的空格，因此您可以同时在该行中尝试
行[1]。strip（）
（我将稍后更新）。我刚刚意识到还有另一个问题，分隔符右侧有逗号。如红色，2,7