learning pandas python data discovery and analysis made easy pdf

which one is best for use, so let's review it.Concat allows the user to append one or more dataframe (depending on how you define the axis) below or next to the table.Merge merges multiple dataframe to specify the same row as the primary key (key).Join, like merge, incorporates two dataframe. But it does not merge by a specified primary key, but is merged by the same column name or row name.Pandas ApplyApply is designed for the pandas series. If you're not familiar with series, you can think of

IntroducedCan a machine tell the variety of flowers according to the photograph? In the machine learning angle, this is actually a classification problem, that is, the machine according to different varieties of flowers of the data to learn, so that it can be unmarked test image data classification.This section, we still start from Scikit-learn, understand the ba

fake_func (P, x):f = np.poly1d (P) #多项式分布的函数return f (x)#残差函数def residuals (p, y, x):Return Y-fake_func (p, x)#随机选了9个点, as Xx = Np.linspace (0, 1, 9)A lot of points #画图的时候需要的 "continuous"X_show = Np.linspace (0, 1, 1000)y0 = Real_func (x)#加入正态分布噪音后的yy1 = [Np.random.normal (0, 0.1) + Y for y in y0]#先随机产生一组多项式分布的参数P0 = Np.random.randn (M)PLSQ = LEASTSQ (residuals, P0, args= (y1, x))Print (' Fitting Parameters: ', plsq[0]) #输出拟合参数Pl.plot (X_show, Real_func (x_show), label= ' real ')Pl.plot (X_show

First, IntroductionAs for regular expressions, I have already made a detailed introduction in the previous (Data Science Learning Codex 31), which summarizes the common functions of the self-contained module re in Python.As a module supported by Python for regular expression related functions, re provides a series of m

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

), and proficient at least one of them and used in multiple projects and have their ownexperiences and experiences;Other references:A. Familiar with common class libraries * proficient in Django architecture and development, and commonly used third-party packages * Familiar with restful API design and use, familiar with nonblocking io and asynchronous IO technologyB. Python fundamentals: Familiar with Io, multithreading and other basic technologiesPS:

Recommend a Visual Web site "Visual Algo": Url= ' https://visualgo.net/en/sorting 'This website gives the principles and processes of various sorting algorithms, which are visualized through dynamic forms. The related pseudo-code are also given, as well as the specific steps to execute to code."Bubble Sort"You need to repeatedly visit the sequence of columns that need to be sorted. The size of the adjacent two items is compared during the visit, and if the order is not correct, two items are exc

Prediction problems in machine learning are usually divided into 2 categories: regression and classification .Simply put, regression is a predictive value, and classification is a label that classifies data.This article describes how to use Python for basic data fitting, and how to analyze the error of fitting results.This example uses a 2-time function with a ra

attribute in the data set. The general situation is somewhere between the two.D. High-dimensional mappingMap properties to high-dimensional space. This is the most precise approach, which completely retains all the information and does not add any additional information. For example, Google, Baidu's CTR Prediction model, pre-processing will be all the variables to deal with this, up to hundreds of millions of dimensions. The benefit of this is that t

Python data type: int type Float decimal Type String strings Boolean type a = True B = False1. A list, also known as an array or a list or array. Its expression is rendered by subscript or index or number.students=[' Zhang San ', ' John Doe ', ' Harry ', ' Zhao Liu ']Print (Students[0])Note: The subscript for the first element is 0, and the last element is subscript 1Cities = []#增加: (Two

"Merge Sort" Here we use recursive algorithm to keep the list in two, base case is no element in the list or only one element, because this sub-list is bound to be a positive sequence, and then gradually merge the two sorted sub-list into a new positive sequence table, until all the elements sorted."This is a process from the bottom up (bottom-up)Divides the list from the middle into two sub-lists until it reaches the bottom, with only one element in the sub-list　　Then, the two sub-lists are mer