July 2017
Intermediate to advanced
398 pages
11h 54m
Chinese
Content preview from Python数据处理
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供机器读取的数据
｜
35
如果你按照上面的提示操作，应该创建好了一个像这样的文件夹：
~/Projects/data_
wrangling/code
。
在基于
Unix
的系统中（
Linux
和
Mac
），
~
符号代表主目录，用命令行访问比较方便。
在
Windows
系统中，主目录位于
Users
文件夹下，所以你的文件夹位置是在
C:\Users\
<your_name>\Projects\data_wrangling
。
在本书的数据仓库中（
https://github.com/jackiekazil/data-wrangling
）可以下载代码示
例，并将其移动到你的项目文件夹中。在阅读本章的过程中，我们假定，从上述仓库
下载的数据与你编写的
Python
代码位于同一文件夹下。这样我们就不必担心文件定位
问题，可以专心研究用
Python
导入数据。
3.1
CSV
数据
我们要学习的第一个机器可读的文件格式是
CSV
。
CSV
文件（简称为
CSV
）是指将数据
列用逗号分隔的文件。文件的扩展名是
.csv
。
另一种数据类型，叫作制表符分隔值（
tab-separated values
，
TSV
）数据，有时也与
CSV
归为一类。
TSV
与
CSV
唯一的不同之处在于，数据列之间的分隔符是制表符（
tab
），而不
是逗号。文件的扩展名通常是
.tsv
，但有时也用
.csv
作为扩展名。从本质上来看，
.tsv
文
件与
.csv
文件在
Python
中的作用是相同的。
如果文件的扩展名是
.tsv
，那么里面包含的很可能是
TSV
数据。如果文件的
扩展名是
.csv
，那么里面包含的可能是 ...
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I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.