Question

这是我正在编写的代码

import csv
import openpyxl

def read_file(fn):
    rows = []

    with open(fn) as f:
        reader = csv.reader(f, quotechar='"',delimiter=",")
        for row in reader:
            if row:                     
                rows.append(row)
    return rows 


replace = {x[0]:x[1:] for x in read_file("replace.csv")}


delete = set( (row[0] for row in read_file("delete.csv")) )  


result = []

input_file="input.csv"
with open(input_file) as f:
    reader = csv.reader(f, quotechar='"')
    for row in reader:
        if row:
            if row[7] in delete:
                continue                                   
            elif row[7] in replace:

                result.append(replace[row[7]])   
            else:
                result.append(row)                       



with open ("done.csv", "w+", newline="") as f:
    w = csv.writer(f,quotechar='"', delimiter= ",")
    w.writerows(result)

这是我的文件：

input.csv：

c1,c2,c3,c4,c5,c6,c7,c8,c9,c10,c11,c12,c13
"-","-","-","-","-","-","-","aaaaa","-","-","bbbbb","-",","
"-","-","-","-","-","-","-","ccccc","-","-","ddddd","-",","
"-","-","-","-","-","-","-","eeeee","-","-","fffff","-",","

这是一个13列的csv。我只对第8和第11领域感兴趣。

这是我的replace.csv：

"aaaaa","11111","22222"

delete.csv：

ccccc

所以我在做的是将replace.csv的第一列（逐行）与input.csv的第八列进行比较，如果匹配，则将input.csv的第八列替换为replace.csv的第二列输入的第11列和replace.csv的第3列对于delete.csv，它逐行比较两个文件，如果找到匹配项，则删除整行。并且如果replace.csv或delete.csv中没有任何行，则按原样打印该行。所以我想要的输出是：

c1,c2,c3,c4,c5,c6,c7,c8,c9,c10,c11,c12,c13
"-","-","-","-","-","-","-",11111,"-","-",22222,"-",","
"-","-","-","-","-","-","-","eeeee","-","-","fffff","-",","

但是当我运行这段代码时，它会给我这样的输出：

c1,c2,c3,c4,c5,c6,c7,c8,c9,c10,c11,c12,c13
11111,22222

我要去哪里错了？我正在尝试更改我之前发布过的问题的程序。由于输入文件已更改，因此我试图更改程序。 https://stackoverflow.com/a/54388144/9279313

Answer 1

@anuj 我认为SafeDev的解决方案是最佳选择，但是如果您不想使用熊猫，只需对代码做些改动即可。

for row in reader:
    if row:
        if row[7] in delete:
            continue                                   
        elif row[7] in replace:
            key = row[7]
            row[7] = replace[key][0]
            row[10]= replace[key][1]
            result.append(row)
        else:
            result.append(row)

希望这可以解决您的问题。

Answer 2

实际上很简单。不用从头开始，只需使用熊猫库即可。从那里开始，更容易处理任何数据集。这是您的操作方式：

编辑：

import pandas as pd

input_csv = pd.read_csv('input.csv')
replace_csv = pd.read_csv('replace.csv', header=None)
delete_csv = pd.read_csv('delete.csv')

r_lst = [i for i in replace_csv.iloc[:, 0]]
d_lst = [i for i in delete_csv]

input2_csv = pd.DataFrame.copy(input_csv)
for i, row in input_csv.iterrows():
    if row['c8'] in r_lst:
        input2_csv.loc[i, 'c8'] = replace_csv.iloc[r_lst.index(row['c8']), 1]
        input2_csv.loc[i, 'c11'] = replace_csv.iloc[r_lst.index(row['c8']), 2]
    if row['c8'] in d_lst:
        input2_csv = input2_csv[input2_csv.c8 != row['c8']]

input2_csv.to_csv('output.csv', index=False)

通过将其转换为具有列名参数的函数，并用这两个参数替换“ c8”和“ c11”，可以使该过程更加动态。

使用python从csv替换和删除列

2 个答案: