described below. The first is the index:#-*-encoding:utf-8-*-import NumPy as Npimport pandas as Pdimport Matplotlib.pyplot as Pltfrom pandas import Series,dataf Rame#series has a reindex function that can rearrange the index so that the order of elements changes obj = Series ([1,2,3,4],index=[' A ', ' B ', ' C ', ' d ']) #注意这里的
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
feasible. Also note that when used reindex(index,method=‘**‘) , index must be monotonous, otherwise it will be thrown ValueError: Must be monotonic for forward fill , such as the last call in the previous example, if index=[‘a‘,‘b‘,‘d‘,‘c‘] the use of the words will not.Delete an item on a specified axisThat is, delete the elements of a Series or the meaning of a row (column) of DataFrame, by means of the object .drop(labels, axis=0) :>>> serd 4.5
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
3686000dtype: int64
This is intuitive, but if you want to display the total value as a single row in the table, you still need to make some minor adjustments.
We need to transform the data and convert this series of numbers into DataFrame so that it can be more easily merged into existing data. The T function allows us to change the data arranged by row to the data arranged by column.
df_sum=pd.DataFrame(data=sum_row).Tdf_sum
The last thing we need to do before calculating the sum is to add
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
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
[Data analysis tool] Pandas function introduction (I), data analysis pandas
If you are using Pandas (Python Data Analysis Library), the following will certainly help you.
First, we will introduce some simple concepts.
DataFrame: row and column data, similar to sheet in Excel or a relational database table
Series: Single Column data
Axis: 0: Row, 1: Column
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
row name, where the debt column is added, but there is no data, so it is Nan Can be debt, assign a value Take the line, with IX You can also use nested dictionaries to create dataframe, which are actually series dictionaries, which are dictionaries themselves, so they are nested dictionaries. Can be like a numpy matrix, transpose Essential functionality Here's a look at what the pandas provides for the convenience of these data struct
the data to convert this series of numbers to dataframe so that it can be easily merged into existing data. The T function allows us to transform the data arranged by rows into columns.
DF_SUM=PD. Dataframe (Data=sum_row). T
Df_sum
The last thing we need to do before we calculate the sum is to add the missing columns. We use Reindex to help us finish. The trick is to add all the columns and let pa
[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
adjustments.
We need to transform the data and convert this series of numbers into DataFrame so that it can be more easily merged into existing data. The T function allows us to change the data arranged by row to the data arranged by column.
df_sum=pd.DataFrame(data=sum_row).Tdf_sum
The last thing we need to do before calculating the sum is to add missing columns. We use reindex to help us complete this process. The trick is to add all the columns a
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
Data analysis and presentation-Pandas data feature analysis and data analysis pandasSequence of Pandas data feature analysis data
The basic statistics (including sorting), distribution/accumulative statistics, and data features (correlation, periodicity, etc.) can be obtained through summarization (lossy process of extracting data features), data mining (Knowledge formation ).
The. sort_index () method so
, 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 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
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