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# #之前已经有很多人写过相关内容, but I have not read before, this crawler is also in accordance with their own ideas written, may be more ugly, please forgive me!I as a novice Python crawler and stock market leek, because of time every night no way to turn billboard data, so I hope to use the Crawler to filter out useful information for my analysis (in fact, I want to lazy ...
element is the index of the item whose index number is smaller than the previous one. So we see that the value of index 2,3 is 1, and the value of index 1
If you want to use the element following the newly inserted index, you need to use the Bfill method
The replacement index can be extended from series to dataframe, not only to replace the row index, but also to replace the column index or even replace both
Second, delete
① Deleting a series Pandas specificall
first, the initial knowledge of pandas
Pandas is a very useful library based on NumPy, which has two unique basic data Structures series (one-dimensional) and dataframe (two-dimensional) that make data operations simpler. Although pandas has two data structures, it is still a library of Python, so some
, time data. And there are calendar features. The datetime, time, and calendar modules are used primarily. #-*-coding:utf-8-*-ImportNumPy as NPImportPandas as PDImportMatplotlib.pyplot as PltImportdatetime as DT fromDatetimeImportDatetimenow=DateTime.Now ()#datetime stores time in millisecondsPrintNow,now.year,now.month,now.day,now.microsecond,'\ n'#print datetime (2015,12,17,20,00,01,555555) #设置一个时间#Datetime.timedelta represents a time difference bet
one-dimensional array in column form5. Row-StackedSplitting numpy arraysRelated functions Hsplit (), Vsplit (), Dsplit (), and split (). We can either divide the array into an array of the same shape, or we can begin to cut the array from the specified position.1. Split horizontallyThe split () function equivalent to calling the parameter Axis=1:2. Split verticallyWhen the parameter Axis=0,split () function also decomposes the array along the vertical axis3. Deep splitThe premise is that there
#-*-coding:utf-8-*-#analysis of food and beverage sales data statistics from __future__ Importprint_functionImportPandas as Pdcatering_sale='.. /data/catering_sale.xls' #Dining Datadata = Pd.read_excel (Catering_sale, Index_col = u'Date')#reading data, specifying "date" as index columndata =
I recently started to learn Python, numpy, scipy, etc. I want to do some data projects, but I have no experience in this area. So I want to know what interesting projects have been done by everyone, or if I have any good options to start with, I recommend the following reply content: (Note: what channels do you use to obtain the knowledge and information that the average person does not know? -He mingke's a
Chapter Nineth Analysis of text data and social media
1 Installation NLTK slightly
2 Filter Stop word name and number
The sample code is as follows:
ImportNLTK # Load English stop word corpus SW = set (Nltk.corpus.stopwords.words (' 中文版 ')) print (' Stop words ', list (sw) [: 7]) # Get the part of the Gutenberg Corpus
File GB = Nltk.corpus.gutenberg print (' Gutenberg files ', gb.fileids () [-5:]) # Tak
Pandas is the preferred library for subsequent content in this book. The pandas can meet the following requirements:
Data structure with automatic or explicit data alignment by axis. This prevents many common errors caused by data misalignment and data from different data
Python data analysis (Basic)First, install the anaconda:https://www.anaconda.com/download/#windowsIi. NumPy (Basic package of scientific calculation)Three, matplotlib (chart)Iv. SciPy (collection of packages for solving various standard problem domains in scientific calculations)V. Pandas (Treatment of structured data)
last=20 multiplier=0.1station_id=1
All station [id=1 name=de Bilt, Id=2name=utrecht]
All sensor [id=1 last=20 multiplier=0.1station_id=1]
Query sensor by station Id=1 last=20multiplier=0.1 station_id=1
Read_sql All station ID name
0 1 De bilt
1 2 Utrecht
[Winerror 32] Another program is using this file and the process is inaccessible. : ' Demo.db '
4 Pony ORM
The ORM package written in Python
Database, db_session
to_sqlsm
# Create SQLite
db = Dat
Data Description:movielens DataSet, which contains 100K movie scores from 943 users and a select 1682 movies . score at least 20 movies per user, data type User ID | item ID | rating | timestamp. Address: https://grouplens.org/datasets/movielens/1. Introduction of Pandas,numpy Package2, read the data: First, if the file is not in the default path, you need to
Hierarchical Indexes Hierarchical indexing means you can have multiple indexes on an array, for example: a bit like a merged cell in Excel, right?Select a subset of the data based on the index to select a subset of the data from the other layer:Select data in the same way as the index in the layer:Multi-index series conversion to Dataframe hierarchical indexes pl
The Basic course has not finished, it came to this, because my usual research is based on data processing. Who says the woman is inferior to the male 650) this.width=650; "src=" Http://img.baidu.com/hi/jx2/j_0011.gif "alt=" J_0011.gif "/>do your own things well done carefully, Hee 650) this.width=650; "src=" Http://img.baidu.com/hi/jx2/j_0003.gif "alt=" J_0003.gif "/>Read the introductory section, download the dat
I now need to automate data collection on the list of articles in a Web site and the actual content in the list, which can get the ID of each article, And each article through a unified interface (parameter with that article ID to get to the corresponding JSON) there is a part of the data need to collect and then analyze data.
Is there any more mature frame or
Ming 6.0 - Name:price, Dtype:float64 -Zhang San 1.2 theReese 1.0 -Harry 2.3 -Chen Jiu 5.0 -Xiao Ming 6.0 +Name:price, Dtype:float64 In general, we often need to value by column, then Dataframe provides loc and Iloc for everyone to choose from, but the difference is between the two.1 Print(frame2)2 Print(frame2.loc['Harry'])#Loc can use the index of the string type, whereas the Iloc can only be of type int3 Print(frame0.iloc[2])4 out[2]: 5 Color Object Price6Zhang San Blue ball 1.27Reese Green
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