使用for循环替换pandas列的每一行中的单元格值(Replace cell values in each row of pandas column using for loop)

使用for循环替换pandas列的每一行中的单元格值(Replace cell values in each row of pandas column using for loop)

请帮我理解我的错误。 我正在尝试更改.csv文件中的一列。 我有.csv文件如下：

sku,name,code k1,aaa,886 k2,bbb,898 k3,ccc,342 k4,ddd,503 k5,eee,401

我想用“sku”列中的“_”符号替换“k”符号。 我写了代码：

import sys import pandas as pd import numpy as np import datetime df = pd.read_csv('cat0.csv') for r in df['sku']: r1 = r.replace('k', '_') df['sku'] = r1 print (df)

但代码会在“sku”列的每一行中插入最后一个值。 所以我得到：

sku name code 0 _5 aaa 886 1 _5 bbb 898 2 _5 ccc 342 3 _5 ddd 503 4 _5 eee 401

我想得到如下：

sku name code 0 _1 aaa 886 1 _2 bbb 898 2 _3 ccc 342 3 _4 ddd 503 4 _5 eee 401

Please, help me understand my error. I'm trying to change one column in my .csv file. I have .csv file as following:

sku,name,code k1,aaa,886 k2,bbb,898 k3,ccc,342 k4,ddd,503 k5,eee,401

I want to replace "k" symbol with the "_" symbol in the "sku" column. I wrote the code:

import sys import pandas as pd import numpy as np import datetime df = pd.read_csv('cat0.csv') for r in df['sku']: r1 = r.replace('k', '_') df['sku'] = r1 print (df)

But the code inserts the last value in every row of the "sku" column. So I get:

sku name code 0 _5 aaa 886 1 _5 bbb 898 2 _5 ccc 342 3 _5 ddd 503 4 _5 eee 401

I want to get as following:

sku name code 0 _1 aaa 886 1 _2 bbb 898 2 _3 ccc 342 3 _4 ddd 503 4 _5 eee 401

最满意答案

您可以在整个列上使用str.replace ：

from io import StringIO import pandas as pd data = """sku,name,code k1,aaa,886 k2,bbb,898 k3,ccc,342 k4,ddd,503 k5,eee,401""" file = StringIO(data) df = pd.read_csv(file) df['sku'] = df['sku'].str.replace('k', '_') print(df)

这会产生

sku name code 0 _1 aaa 886 1 _2 bbb 898 2 _3 ccc 342 3 _4 ddd 503 4 _5 eee 401

You can use str.replace on the whole column:

from io import StringIO import pandas as pd data = """sku,name,code k1,aaa,886 k2,bbb,898 k3,ccc,342 k4,ddd,503 k5,eee,401""" file = StringIO(data) df = pd.read_csv(file) df['sku'] = df['sku'].str.replace('k', '_') print(df)

This yields

sku name code 0 _1 aaa 886 1 _2 bbb 898 2 _3 ccc 342 3 _4 ddd 503 4 _5 eee 401