15

我对 Python 很陌生。我知道这已经被问过了，我很抱歉，但这种新情况的不同之处在于字符串之间的空格不相等。我有一个名为coord的文件，其中包含以下空格分隔的字符串：

   1  C       6.00    0.000000000    1.342650315    0.000000000
   2  C       6.00    0.000000000   -1.342650315    0.000000000
   3  C       6.00    2.325538562    2.685300630    0.000000000
   4  C       6.00    2.325538562   -2.685300630    0.000000000
   5  C       6.00    4.651077125    1.342650315    0.000000000
   6  C       6.00    4.651077125   -1.342650315    0.000000000
   7  C       6.00   -2.325538562    2.685300630    0.000000000
   8  C       6.00   -2.325538562   -2.685300630    0.000000000
   9  C       6.00   -4.651077125    1.342650315    0.000000000
  10  C       6.00   -4.651077125   -1.342650315    0.000000000
  11  H       1.00    2.325538562    4.733763602    0.000000000
  12  H       1.00    2.325538562   -4.733763602    0.000000000
  13  H       1.00   -2.325538562    4.733763602    0.000000000
  14  H       1.00   -2.325538562   -4.733763602    0.000000000
  15  H       1.00    6.425098097    2.366881801    0.000000000
  16  H       1.00    6.425098097   -2.366881801    0.000000000
  17  H       1.00   -6.425098097    2.366881801    0.000000000
  18  H       1.00   -6.425098097   -2.366881801    0.000000000

请注意第一列中每个字符串开头之前的空格。所以我尝试了以下将其转换为 csv 的顺序：

with open('coord') as infile, open('coordv', 'w') as outfile:
    outfile.write(infile.read().replace("  ", ", "))

# Unneeded columns are deleted from the csv

input = open('coordv', 'rb')
output = open('coordcsvout', 'wb')
writer = csv.writer(output)
for row in csv.reader(input):
    if row:
        writer.writerow(row)
input.close()
output.close()

with open("coordcsvout","rb") as source:
    rdr= csv.reader( source )
    with open("coordbarray","wb") as result:
        wtr= csv.writer(result)
        for r in rdr:
            wtr.writerow( (r[5], r[6], r[7]) )

当我运行脚本时，我在脚本的第一部分得到了coordv的以下内容，这当然是非常错误的：

,  1, C, , ,  6.00, , 0.000000000, , 1.342650315, , 0.000000000
,  2, C, , ,  6.00, , 0.000000000,  -1.342650315, , 0.000000000
,  3, C, , ,  6.00, , 2.325538562, , 2.685300630, , 0.000000000
,  4, C, , ,  6.00, , 2.325538562,  -2.685300630, , 0.000000000
,  5, C, , ,  6.00, , 4.651077125, , 1.342650315, , 0.000000000
,  6, C, , ,  6.00, , 4.651077125,  -1.342650315, , 0.000000000
,  7, C, , ,  6.00,  -2.325538562, , 2.685300630, , 0.000000000
,  8, C, , ,  6.00,  -2.325538562,  -2.685300630, , 0.000000000
,  9, C, , ,  6.00,  -4.651077125, , 1.342650315, , 0.000000000
, 10, C, , ,  6.00,  -4.651077125,  -1.342650315, , 0.000000000
, 11, H, , ,  1.00, , 2.325538562, , 4.733763602, , 0.000000000
, 12, H, , ,  1.00, , 2.325538562,  -4.733763602, , 0.000000000
, 13, H, , ,  1.00,  -2.325538562, , 4.733763602, , 0.000000000
, 14, H, , ,  1.00,  -2.325538562,  -4.733763602, , 0.000000000
, 15, H, , ,  1.00, , 6.425098097, , 2.366881801, , 0.000000000
, 16, H, , ,  1.00, , 6.425098097,  -2.366881801, , 0.000000000
, 17, H, , ,  1.00,  -6.425098097, , 2.366881801, , 0.000000000
, 18, H, , ,  1.00,  -6.425098097,  -2.366881801, , 0.000000000

我在 .replace 中尝试了不同的可能性，但没有成功，到目前为止，我还没有找到任何关于如何做到这一点的信息来源。从此坐标文件中获取逗号分隔值的最佳方法是什么？我感兴趣的是使用python中的csv模块来选择4：6列，最后使用numpy导入它们，如下所示：

from numpy import genfromtxt
cocmatrix = genfromtxt('input', delimiter=',')

如果有人可以帮助我解决这个问题，我会很高兴。

4

8 回答 8

14

您可以使用 csv：

import csv

with open(ur_infile) as fin, open(ur_outfile, 'w') as fout:
    o=csv.writer(fout)
    for line in fin:
        o.writerow(line.split())
于 2013-11-03T23:35:03.160 回答
8

您可以使用python pandas，我已将您的数据写入data.csv：

import pandas as pd
>>> df = pd.read_csv('data.csv',sep='\s+',header=None)
>>> df
     0  1  2         3         4  5
0    1  C  6  0.000000  1.342650  0
1    2  C  6  0.000000 -1.342650  0
2    3  C  6  2.325539  2.685301  0
3    4  C  6  2.325539 -2.685301  0
4    5  C  6  4.651077  1.342650  0
5    6  C  6  4.651077 -1.342650  0
...

这样做的好处是可以访问您可以使用的底层 numpy 数组df.values：

>>> type(df.values)
<type 'numpy.ndarray'>

要使用逗号分隔符保存数据框：

>>> df.to_csv('data_out.csv',header=None)

Pandas 是一个用于管理大量数据的出色库，作为奖励，它与 numpy 配合得很好。这也很有可能比使用csv模块快得多。

于 2013-11-03T23:41:27.817 回答
7

用这个替换你的第一位。它不是超级漂亮，但它会给你一个 csv 格式。

with open('coord') as infile, open('coordv', 'w') as outfile:
    for line in infile:
        outfile.write(" ".join(line.split()).replace(' ', ','))
        outfile.write(",") # trailing comma shouldn't matter

如果您希望 outfile 将所有内容放在不同的行上，您可以 outfile.write("\n")在 for 循环的末尾添加，但我认为您的代码不会像这样使用它。

于 2013-11-03T23:30:02.530 回答
1 
>>> a = 'cah  1  C       6.00    0.000000000    1.342650315    0.000000000'
=>  a = 'cah  1  C       6.00    0.000000000    1.342650315    0.000000000'

>>> a.split()
=>  ['cah', '1', 'C', '6.00', '0.000000000', '1.342650315', '0.000000000']

>>> ','.join(a.split())
=>  'cah,1,C,6.00,0.000000000,1.342650315,0.000000000'

>>> ['"' + x + '"' for x in a.split()]
=>  ['"cah"', '"1"', '"C"', '"6.00"', '"0.000000000"', '"1.342650315"', '"0.000000000"']

>>> ','.join(['"' + x + '"' for x in a.split()]
=>  '"cah","1","C","6.00","0.000000000","1.342650315","0.000000000"'
于 2013-11-04T00:01:22.650 回答
1

用于将“空格”转换为“，”

仅将文件名填写为您想要的

with open('filename') as infile, open('output', 'w') as outfile:
    outfile.write(infile.read().replace(" ", ","))

用于将“，”转换为“空格”

with open('filename') as infile, open('output', 'w') as outfile: outfile.write(infile.read().replace(",", " "))

于 2019-10-14T18:27:46.017 回答
0

为什么不逐行读取文件？将一行拆分为一个列表，然后用“，”重新加入一个列表。

于 2013-11-03T23:51:04.670 回答
0

csv 模块很好，或者这是一种没有的方法：

#!/usr/local/cpython-3.3/bin/python

with open('input-file.csv', 'r') as infile, open('output.csv', 'w') as outfile:
    for line in infile:
        fields = line.split()
        outfile.write('{}\n'.format(','.join(fields)))
于 2013-11-04T00:41:55.443 回答
0

用于在一个 CSV 中合并多个文本文件

import csv
import os
for x in range(0,n):            #n = max number of files 
    with open('input{}.txt'.format(x)) as fin, open('output.csv', 'a') as fout:
       csv_output=csv.writer(fout)
       for line in fin:
            csv_output.writerow(line.split())
于 2019-11-22T10:18:49.670 回答