数据科学【三】：dataframe基本操作（二）

数据科学【三】：dataframe基本操作（二）

google api

使用google book api (https://developers.google.com/books/docs/overview)获得数据。也就是拼接url查询信息。可能需要。

示例：查询相应主体的书籍

注意：json.loads()返回的是json对象

import requests
import json

"""
    Google Books Api
    See: https://developers.google.com/books/
"""

def get(topic=""):
    BASEURL = 'https://www.googleapis.com/books/v1/volumes'
    headers = {'Content-Type': 'application/json'}

    response = requests.get(BASEURL + "?q=" + topic, headers=headers)

    if response.status_code == 200:
        return json.loads(response.content.decode('utf-8'))

    return response

python = get("Python")
data_science = get("Data Science")
data_analytics = get("Data Analysis")
machine_learning = get("Machine Learning")
deep_learning = get("Deep Learning")

json转dataframe

使用json_normalize函数。

def json2df(book_json):
    return pd.json_normalize(book_json['items'])

python_df = json2df(python)
data_science_df = json2df(data_science)
data_analytics_df = json2df(data_analytics)
machine_learning_df = json2df(machine_learning)
deep_learning_df = json2df(deep_learning)

python_df.to_csv("python.csv", index=False)
data_science_df.to_csv("data_science.csv", index=False)
data_analytics_df.to_csv("data_analytics.csv", index=False)
machine_learning_df.to_csv("machine_learning.csv", index=False)
deep_learning_df.to_csv("deep_learning.csv", index=False)

dataframe重命名列

使用dataframe对象的rename函数。

python_df.rename(columns={'volumeInfo.title':'Title', 'volumeInfo.authors':'Authors'}, inplace=True)
data_science_df.rename(columns={'volumeInfo.title':'Title', 'volumeInfo.authors':'Authors'}, inplace=True)
data_analytics_df.rename(columns={'volumeInfo.title':'Title', 'volumeInfo.authors':'Authors'}, inplace=True)
machine_learning_df.rename(columns={'volumeInfo.title':'Title', 'volumeInfo.authors':'Authors'}, inplace=True)
deep_learning_df.rename(columns={'volumeInfo.title':'Title', 'volumeInfo.authors':'Authors'}, inplace=True)

dataframe添加列

使用concat函数。
示例：为每个主题的dataframe添加一个“主题”列。

python_df['Topic'] = pd.Series(['Python']*python_df.shape[0])
data_science_df['Topic'] = pd.Series(['Data Science']*data_science_df.shape[0])
data_analytics_df['Topic'] = pd.Series(['Data Analysis']*data_analytics_df.shape[0])
machine_learning_df['Topic'] = pd.Series(['Machine Learning']*machine_learning_df.shape[0])
deep_learning_df['Topic'] = pd.Series(['Deep Learning']*deep_learning_df.shape[0])

all_df = pd.concat([python_df, data_science_df, data_analytics_df, machine_learning_df, deep_learning_df])

dataframe转csv

使用to_csv函数。

all_df.to_csv("all_topics.csv", index=False)

根据值筛选dataframe行

使用str加string函数

示例：获得所有title 包含data的行

# your code here
contain_data_df = all_df[all_df['Title'].str.lower().str.contains("data")]
contain_data_df.head()

	kind	id	etag	selfLink	Title	volumeInfo.subtitle	Authors	volumeInfo.publishedDate	volumeInfo.description	volumeInfo.industryIdentifiers	...	volumeInfo.categories	saleInfo.listPrice.amount	saleInfo.listPrice.currencyCode	saleInfo.retailPrice.amount	saleInfo.retailPrice.currencyCode	saleInfo.buyLink	saleInfo.offers	accessInfo.epub.acsTokenLink	Topic	accessInfo.pdf.acsTokenLink
7	books#volume	6omNDQAAQBAJ	8i8xnUEyo14	https://www.googleapis.com/books/v1/volumes/6o...	Python Data Science Handbook	Essential Tools for Working with Data	[Jake VanderPlas]	2016-11-21	For many researchers, Python is a first-class ...	[{'type': 'ISBN_13', 'identifier': '9781491912...	...	[Computers]	59.99	USD	59.99	USD	https://play.google.com/store/books/details?id...	[{'finskyOfferType': 1, 'listPrice': {'amountI...	NaN	Python	NaN
0	books#volume	vfi3DQAAQBAJ	Q0KYt+x/bgk	https://www.googleapis.com/books/v1/volumes/vf...	R for Data Science	Import, Tidy, Transform, Visualize, and Model ...	[Hadley Wickham, Garrett Grolemund]	2016-12-12	"This book introduces you to R, RStudio, and t...	[{'type': 'ISBN_13', 'identifier': '9781491910...	...	[Computers]	NaN	NaN	NaN	NaN	NaN	NaN	NaN	Data Science	NaN
1	books#volume	TFpVDwAAQBAJ	MqNMwqcnbUk	https://www.googleapis.com/books/v1/volumes/TF...	Data Science	NaN	[John D. Kelleher, Brendan Tierney]	2018-04-13	A concise introduction to the emerging field o...	[{'type': 'ISBN_13', 'identifier': '9780262535...	...	[Computers]	NaN	NaN	NaN	NaN	NaN	NaN	NaN	Data Science	NaN
2	books#volume	6omNDQAAQBAJ	86otz4UmKRE	https://www.googleapis.com/books/v1/volumes/6o...	Python Data Science Handbook	Essential Tools for Working with Data	[Jake VanderPlas]	2016-11-21	For many researchers, Python is a first-class ...	[{'type': 'ISBN_13', 'identifier': '9781491912...	...	[Computers]	59.99	USD	59.99	USD	https://play.google.com/store/books/details?id...	[{'finskyOfferType': 1, 'listPrice': {'amountI...	NaN	Data Science	NaN
3	books#volume	xb29DwAAQBAJ	QKJ7stkk3Ac	https://www.googleapis.com/books/v1/volumes/xb...	Introduction to Data Science	Data Analysis and Prediction Algorithms with R	[Rafael A. Irizarry]	2019-11-20	Introduction to Data Science: Data Analysis an...	[{'type': 'ISBN_13', 'identifier': '9781000708...	...	[Mathematics]	NaN	NaN	NaN	NaN	NaN	NaN	http://books.google.com/books/download/Introdu...	Data Science	http://books.google.com/books/download/Introdu...

5 rows × 52 columns

map加lambda表达式

示例：筛选作者姓或名首字母为E的所有行

author_e_df = all_df[all_df['Authors'].map(lambda row: any(map(lambda x: x.split()[0][0]=='E' or x.split()[1][0]=='E', row)))]
author_e_df.head()

	kind	id	etag	selfLink	Title	volumeInfo.subtitle	Authors	volumeInfo.publishedDate	volumeInfo.description	volumeInfo.industryIdentifiers	...	volumeInfo.categories	saleInfo.listPrice.amount	saleInfo.listPrice.currencyCode	saleInfo.retailPrice.amount	saleInfo.retailPrice.currencyCode	saleInfo.buyLink	saleInfo.offers	accessInfo.epub.acsTokenLink	Topic	accessInfo.pdf.acsTokenLink
7	books#volume	xDszEAAAQBAJ	ju27MhIAQrM	https://www.googleapis.com/books/v1/volumes/xD...	Build a Career in Data Science	NaN	[Emily Robinson, Jacqueline Nolis]	2020-03-06	Summary You are going to need more than techni...	[{'type': 'ISBN_13', 'identifier': '9781638350...	...	[Computers]	28.99	USD	28.99	USD	https://play.google.com/store/books/details?id...	[{'finskyOfferType': 1, 'listPrice': {'amountI...	http://books.google.com/books/download/Build_a...	Data Science	NaN
7	books#volume	fBPEAgAAQBAJ	zEKoyMUn6e8	https://www.googleapis.com/books/v1/volumes/fB...	Beginning Statistics with Data Analysis	NaN	[Frederick Mosteller, Stephen E. Fienberg, Rob...	2013-11-20	This introduction to the world of statistics c...	[{'type': 'ISBN_13', 'identifier': '9780486782...	...	[Mathematics]	24.95	USD	14.72	USD	https://play.google.com/store/books/details?id...	[{'finskyOfferType': 1, 'listPrice': {'amountI...	http://books.google.com/books/download/Beginni...	Data Analysis	http://books.google.com/books/download/Beginni...
3	books#volume	NP5bBAAAQBAJ	evXnYOuFPGY	https://www.googleapis.com/books/v1/volumes/NP...	Introduction to Machine Learning	NaN	[Ethem Alpaydin]	2014-08-29	The goal of machine learning is to program com...	[{'type': 'ISBN_13', 'identifier': '9780262028...	...	[Computers]	NaN	NaN	NaN	NaN	NaN	NaN	NaN	Machine Learning	NaN
4	books#volume	AGQ4DQAAQBAJ	4KxWueVGUyI	https://www.googleapis.com/books/v1/volumes/AG...	Machine Learning	The New AI	[Ethem Alpaydin]	2016-10-07	A concise overview of machine learning—compute...	[{'type': 'ISBN_13', 'identifier': '9780262529...	...	[Computers]	NaN	NaN	NaN	NaN	NaN	NaN	NaN	Machine Learning	NaN
5	books#volume	LrT4DwAAQBAJ	RCyLWjQWJQQ	https://www.googleapis.com/books/v1/volumes/Lr...	Introduction to Deep Learning	NaN	[Eugene Charniak]	2019-01-29	A project-based guide to the basics of deep le...	[{'type': 'ISBN_13', 'identifier': '9780262039...	...	[Computers]	NaN	NaN	NaN	NaN	NaN	NaN	NaN	Deep Learning	NaN

5 rows × 52 columns