,. IX features are more powerful, it allows us to mix the subscript and the name of the selection. It can be said that it covers all the previous uses. Basically change the front to Df.ix can be successful, but one thing is thatDf.ix [[.. 1 ...], [.. 2.]], the 1 box must be unified, must also be subscript or name, 2 box is also the same. BTW, the 1 box is used to specify that the row,2 box is the specified column, and all of the above methods are, of
The Pandas object has some common mathematical and statistical methods. For example, the sum () method, which makes the column subtotal: the sum () method passed in Axis=1 is specified as a horizontal summary, which is subtotal: Idxmax () gets the index of the maximum value: There is also a rollup that is cumulative, cumsum (), compared to it and Su The difference between M ():The unique () method is used to return only values in the data: the Value_
I believe many people like me in the process of learning Python,pandas data selection and modification has a great deal of confusion (perhaps by the Matlab) impact ...
To this day finally completely figure out ...
Let's start with a data box manually.
Import NumPy as NP
import pandas as PD
DF = PD. Dataframe (Np.arange (0,60,2). Reshape (10,3), columns=list (' abc ')DF is such a drop
So what are the three
Original English: 09-lesson
Export data from Microsoft's SQL database to CSV, Excel, or text files.
# import library Import
pandas as PD
import sys from
sqlalchemy import create_engine, MetaData, Table, select
Print (' Python version ' + sys.version)
print (' Pandas version ' + pd.__version__)
Python version 3.6.1 | Packaged by Conda-forge | (Default, Mar 2017, 21:57:00)
[GCC 4.2.1 compatible Apple LLVM
-assign the value of the # line, you can use the row name or the number of rows to choose Print frame1.ix[' two '] #为列赋值, if it is a series, the index can be specified after the exact value frame1[' d '] = Series ([100,200,300],index = [' Two ', ' one ', ' three ']) print frame1# Delete column with del frame1[' d '] #警告: A series view is selected by column name, is not a copy and can be copied using the series copy methodAnother common structure is a
Pandas basics, pandas
Pandas is a data analysis package built based on Numpy that contains more advanced data structures and tools.
Similar to Numpy, the core is ndarray, and pandas is centered around the two core data structures of Series and DataFrame. Series and DataFrame correspond to one-dimensional sequences and
browsing data. The default value is 5.
Df. sample (n): Randomly browses n rows of data. The default value is 5 rows.
Df. shape: the number of rows and columns of the tuple type)
Df. describe (): Calculate the evaluation data Trend
Df.info (): memory and Data Type
3. It is easy to add columns to DataFrame in DataFrame. The following describes several methods.
Simple Method
Directly add new columns and assign values
Df ['new _ column'] = 1
Calculation Method
Df ['temp _ diff '] = df ['tem
section "Getting Started with data structures (Intro to data Structures)". Open this page next to your Jupyter notebook. When you read the document, write down (rather than copy) the code and execute it in the notebook. As you execute your code, explore these operations and try to explore new ways to use them.Then select the section "Index and select data (indexing, Selecting data)". Create a new Jupyter notebook, write and execute the code, and then explore the different actions you learned. T
This article mainly introduces you to the pandas in Python. Dataframe to exclude specific lines of the method, the text gives a detailed example code, I believe that everyone's understanding and learning has a certain reference value, the need for friends to see together below. When you use Python for data analysis, one of the most frequently used structures is the dataframe of pandas, about
Python traversal pandas data method summary, python traversal pandas
Preface
Pandas is a python data analysis package that provides a large number of functions and methods for fast and convenient data processing. Pandas defines two data types: Series and DataFrame, which makes data operations easier. Series is a one-di
Teach you how to use Pandas pivot tables to process data (with learning materials) and pandas learning materials
Source: bole online-PyPer
Total2203 words,Read5Minutes.This article mainly explains pandas's pivot_table function and teaches you how to use it for data analysis.
Introduction
Most people may have experience using pivot tables in Excel. In fact, Pandas
Pandas Quick Start (3) and pandas Quick Start
This section mainly introduces the Pandas data structure, this article cited URL: https://www.dataquest.io/mission/146/pandas-internals-series
The data used in this article comes from: https://github.com/fivethirtyeight/data/tree/master/fandango
This data mainly describes
[Data cleansing]-clean "dirty" data in Pandas (3) and clean pandasPreview Data
This time, we use Artworks.csv, And we select 100 rows of data to complete this content. Procedure:
DataFrame is the built-in data display structure of Pandas, and the display speed is very fast. With DataFrame, we can quickly preview and analyze data. The Code is as follows:
import pandas
Pandas data analysis (data structure) and pandas Data Analysis
This article mainly expands pandas data structures in the following two directions: Series and DataFrame (corresponding to one-dimensional arrays and two-dimensional arrays in Series and numpy)
1. First, we will introduce how to create a Series.
1) A sequence can be created using an array.
For example
The previous Pandas array (Pandas Series)-(3) Vectorization, said that when the two Pandas series were vectorized, if a key index was only in one of the series , the result of the calculation is nan , so what is the way to deal with nan ?1. Dropna () method:This method discards all values that are the result of NaN , which is equivalent to calculating only the va
Sometimes you need to do some work on the values in the Pandas series , but without the built-in functions, you can write a function yourself, using the Pandas series 's apply method, You can call this function on each value inside, and then return a new SeriesImport= PD. Series ([1, 2, 3, 4, 5])def add_one (x): return x + 1print s.apply ( Add_one)# results:0 6dtype:int64A chestnut:Names =PD. Serie
Data conversionDelete duplicate elements The duplicated () function of the Dataframe object can be used to detect duplicate rows and return a series object with the Boolean type. Each element pairsshould be a row, if the row repeats with other rows (that is, the row is not the first occurrence), the element is true, and if it is not repeated with the preceding, the metaThe vegetarian is false.A Series object that returns an element as a Boolean is of great use and is particularly useful for fil
, how to do? For more information please go to other blogs, where more detailed instructions are available .Pandas import time data for format conversion Draw multiple graphs on one canvas and add legends1 fromMatplotlib.font_managerImportfontproperties2Font = fontproperties (fname=r"C:\windows\fonts\STKAITI. TTF", size=14)3colors = ["Red","Green"]#the color used to specify the line4Labels = ["Jingdong","12306"]#used to specify the legend5Plt.plot (
The pandas Series is much more powerful than the numpy array , in many waysFirst, the pandas Series has some methods, such as:The describe method can give some analysis data of Series :Import= PD. Series ([1,2,3,4]) d = s.describe ()Print (d)Count 4.000000mean 2.500000std 1.290994min 1.00000025% 1.75000050% 2.50000075% 3.250000max 4.000000dtype:float64Second, the bigges
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