如何使用python提取csv文件的最大值和最小值

Question

我有一个从包含3列

的csv文件中读取的python脚本

• 日期
• minTemprature
• maxTemperature

我需要提取

1. 最小值存在于minTemprature列
2. maxTemperature列中存在的最大值

我的脚本中的错误在哪里？

的代码：

function GetScores(url, onCountTotal) {
    var FBUrl, TWUrl, LNUrl, GLUrl, PIUrl;
    var url1 = "";
    url1 = encodeURIComponent(url1 || url);
    //Fetch counters from PInterest
    var pi_like_count = 0;
    PIUrl = "https://api.pinterest.com/v1/urls/count.json?url=" + url1 + "&format=jsonp" + '&callback=?';
    $.ajax({
        type: 'GET',
        dataType: 'json',
        url: PIUrl,
        success: function (data) {
            pi_like_count = data.count;
            var fb_share_count = 0;
            FBUrl = "https://graph.facebook.com/?id=" + url1 + "&format=json";
            $.ajax({
                type: 'GET',
                dataType: 'json',
                url: FBUrl,
                success: function (data) {
                    fb_share_count = data.share.share_count;
                    var totalshare = parseInt(fb_share_count) + parseInt(pi_like_count);
                    onCountTotal(totalshare);
                    //alert(fb_share_count + ' facebook');
                },
                error: function (data) {
                    onCountTotal(-1);
                },
                async: true
            });
        },
        error: function (req, status, error) {
            onCountTotal(-1);
        },
        async: true
    });
}

//EXAMPLE HERE CALL FUNCTION WITH CALLBACK
GetScores("http://www.google.com", function (count) {
    alert("Count = " + count);
});

Answer 1

如果您只需要最小值和最大值，您可以执行以下操作：

编辑：根据评论更改了代码

import csv

with open("C:/Users/test/Documents/R_projects/homework/rdu-weather-history.csv") as myfile:
    myreader=csv.reader(myfile,delimiter=';')
    content = list(myreader)
    minTemp = min([int(elem[1]) for elem in content])
    maxTemp = max([int(elem[2]) for elem in content])

print("the min value is : ", minTemp)
print("the max value is : ", maxTemp) 

Answer 2

使用Numpy

import numpy as np
data = np.loadtxt("C:/Users/test/Documents/R_projects/homework/rdu-weather-history.csv", delimiter=',', usecols=(1,2)

min_min_T = np.min(data[:, 0])
max_max_T = np.max(data[:, 1])