Question

由于列和用户列表不同，因此会发出错误

＆＃34; ValueError异常＆＃34; Usecols与名称不匹配。

我怎样才能使用＆＃39;如果列存在于csv？

中

csv示例：

*  {
    box-sizing: border-box;
}

body {
         background-color: #ffffff; 
         color: #666666;
         background-image: url(../images/background.jpg);
         font-family: Verdana, Arial, sans-serif;
}

#wrapper {
         background-color: #90c7e3;
         width: 80%; 
         min-width: 700px;
         max-width: 1024px;
         box-shadow: 10px 10px 5px #888888;
         margin-right: auto;
         margin-left: auto;
}

header {
         background-color: #000033;
         color: #ffffff;
         font-family: Georgia, "Times New Roman", serif;
}

h1 {
         background-image: url(../images/sunset.jpg);
         background-repeat: no-repeat;
         background-position: right; 
         padding-left: 20px;
         height: 72px; 
         line-height: 200%;
         margin-bottom: 0;
}

nav {
         float: left;
         width: 160px;
         padding-top: 20px;
         padding-right: 5px;
         padding-left: 20px;
         padding-bottom: 0;
         padding: 5px; 
         font-weight: bold;

}

nav a {
         text-decoration: none;
}

nav a:hover { 
     color: #ffffff;
}

nav a:link: {
    color: #000033;
}

nav a:visited {
    color: #344873;
}

nav ul {
    list-style-type: none;
    margin: 0;
    padding-left: 0;
}

main {
         background-color: #ffffff;
         margin-left: 170px;
         padding-top: 1px;
         padding-bottom: 1px;
         padding-left: 20px;
         padding-right: 20px;
         display: block; 
}

h2 {
         color: #3399cc;
         font-family: Georgia, "Times New Roman", serif;
}

h3 {
    color: #000033; 
}

dt {
         color: #000033;
         font-weight: bold;
}

.resort {
         color: #000033;
         font-size: 1.2em;
}


#homehero {
         background-image: url(../images/coast.jpg);
         height: 300px;
         background-size: 100% 100%;
         margin-right: 0;
         margin-left: 170px;
         background-repeat: no-repeat; 
}

#yurthero {
         background-image: url(../images/yurt.jpg);
         background-size: 100% 100%;
         background-repeat: no-repeat;
         height: 300px;
         margin-left: 170px;
}

#trailhero {
         background-image: url(../images/trail.jpg);
         height: 300px;
         background-size: 100% 100%;
         background-repeat: no-repeat;
         margin-left: 170px;
}


footer {
         background-color: #ffffff;
         margin-left: 170px;
         font-size: .70em;
         font-style: italic;
         text-align: center;
         padding: 10px; 
}

header, nav, main, footer {
     display: block;
}

阅读csv：

df.csv

AB,CD,EF,GH
foo,20160101,a,1
foo,20160102,a,3
foo,20160103,a,5

这就是我想要的：

import pandas as pd


df = pd.read_csv('df.csv', 
    header=0,usecols=["AB", "CD", "IJ"])

忽略＆＃34; IJ＆＃34;。

Answer 1

使用lambda中的usecols跳过不在csv中的列：

import pandas as pd
from io import StringIO

txt = """AB,CD,EF,GH
foo,20160101,a,1
foo,20160102,a,3
foo,20160103,a,5"""

usecols = ['AB', 'CD', 'IJ']

df = pd.read_csv(StringIO(txt), usecols=lambda c: c in set(usecols))

print(df)

    AB        CD
0  foo  20160101
1  foo  20160102
2  foo  20160103

Answer 2

通常导入csv

import pandas as pd
from io import StringIO

txt = """AB,CD,EF,GH
foo,20160101,a,1
foo,20160102,a,3
foo,20160103,a,5"""

df = pd.read_csv(StringIO(txt))

print(df)

    AB        CD EF  GH
0  foo  20160101  a   1
1  foo  20160102  a   3
2  foo  20160103  a   5

带有reindex

的

intersection

usecols = ['AB', 'CD', 'IJ']
df.reindex_axis(df.columns.intersection(usecols), 1)

    AB        CD
0  foo  20160101
1  foo  20160102
2  foo  20160103

Pandas - 当csv中存在列时使用usecols

2 个答案: