title: "Mathematical functions" date: 2026-05-24T13:52:09Z Mathematical functions 1import numpy as np 1np.version '1.11.2' 1__author__ = "kyubyong. kbpark.linguist@gmail.com. https://github.com/kyubyong" Trigonometric functions Q1. Calculate sine, cosine, and tangent of x, element-wise. 1x = np.array([0., 1., 30, …

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title: "9.scipy-ndimage" date: 2026-05-24T14:11:26Z 1import numpy as np 2import pylab as pl 图像处理-ndimage 形态学图像处理 1import numpy as np 2 3def expand_image(img, value, out=None, size = 10): 4 if out is None: 5 w, h = img.shape 6 out = np.zeros((wsize, hsize),dtype=np.uint8) 7 8 tmp = …

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title: "2天学会Pandas" date: 2026-05-24T14:09:31Z 2天学会Pandas 目录 0.导语 1.Series 2.DataFrame 2.1 DataFrame的简单运用 3.pandas选择数据 3.1 实战筛选 3.2 筛选总结 4.Pandas设置值 4.1 创建数据 4.2 根据位置设置loc和iloc 4.3 根据条件设置 4.4 按行或列设置 4.5 添加Series序列(长度必须对齐) 4.6 设定某行某列为特定值 4.7 修改一整行数据 5.Pandas处理丢失数据 5.1 创建含NaN的矩阵 5.2 删除掉有NaN的行或列 5.3 替换NaN值为0或者其他 5.4 是否有缺 …

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title: "Pandas练习题50题" date: 2026-05-24T14:09:49Z Pandas练习题50题 作者：王大毛，和鲸社区 出处：https://www.kesci.com/home/project/5ddc974ef41512002cec1dca 修改：黄海广 Pandas 是基于 NumPy 的一种数据处理工具，该工具为了解决数据分析任务而创建。Pandas 纳入了大量库和一些标准的数据模型，提供了高效地操作大型数据集所需的函数和方法。 这些练习着重DataFrame和Series对象的基本操作，包括数据的索引、分组、统计和清洗。 基本操作 1.导入 Pandas 库并简写为 pd， …

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Question 1 Question: Write a program which will find all such numbers which are divisible by 7 but are not a multiple of 5, between 2000 and 3200 (both included).The numbers obtained should be printed in a comma-separated sequence on a single line. Hints: Consider use range(#begin, #end) method. Main author's Solution: …

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Question 31 Question: Define a function which can print a dictionary where the keys are numbers between 1 and 20 (both included) and the values are square of keys. Hints: 1Use dict[key]=value pattern to put entry into a dictionary.Use ** operator to get power of a number.Use range() for loops. Main Author's Solution: …

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Question 38 Question: With a given tuple (1,2,3,4,5,6,7,8,9,10), write a program to print the first half values in one line and the last half values in one line. Hints: Use [n1:n2] notation to get a slice from a tuple. Main Author's Solution: Python 2 1tp = (1,2,3,4,5,6,7,8,9,10) 2tp1 = tp[:5] 3tp2 = tp[5:] 4print tp1 …

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Question 44 Question: Write a program which can map() to make a list whose elements are square of numbers between 1 and 20 (both included). Hints: Use map() to generate a list. Use lambda to define anonymous functions. Main Author's Solution: Python 2 1squaredNumbers = map(lambda x: x**2, range(1,21)) 2print …

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Question 47 Question Define a class named Circle which can be constructed by a radius. The Circle class has a method which can compute the area. Hints Use def methodName(self) to define a method. Main author's Solution: Python 2 1class Circle(object): 2 def init(self, r): 3 self.radius = r 4 5 def area(self): 6 …

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Question 51 Question Write a function to compute 5/0 and use try/except to catch the exceptions. Hints Use try/except to catch exceptions. Main author's Solution: Python 2 1def throws(): 2 return 5/0 3 4try: 5 throws() 6except ZeroDivisionError: 7 print "division by zero!" 8except Exception, err: 9 print 'Caught an …

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