12 2017 档案
摘要:A histogram is an accurate representation of the distribution of numerical data. Y axis is the occurances, X axis is the % of daily return. There are
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摘要:In React, when you want to set the state which calculation depends on the current state, using an object can lead to state inconsistency. This is due
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摘要:This lesson takes the concept of render props and migrates it over to streaming props by keeping the same example and simple refactoring the Togglecom
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摘要:If you hard-code a stream of props to target a specific prop, it becomes impossible to reuse that stream with any other components. Configuring your p
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摘要:Functions created with mapPropsStream canned be composed together to build up powerful streams. Bring in the compose helper from Recompose then simply
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摘要:Rather than using Components to push streams into other Components, mapPropsStream allows you to create functions that can wrap components to create s
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摘要:You can decouple the parent stream Component from the mapped React Component by using props.children instead. This process involves mapping the stream
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摘要:Combining input streams then using scan to track the results is a common scenario when coding with streams. This lesson walks you through setting up t
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摘要:Events are the beginning of most every stream. Recompose provides a createEventHandler function to help your create handler and stream pairs. Once the
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摘要:Loading data using RxJS is simple using Observable.ajax. This lesson shows you how to take the ajax response and pass it along the stream to use as pr
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摘要:When you declare your Component and Props in JSX, you can pass those props along to your RxJS stream. This is typically done using switchMap or combin
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摘要:Recompose provides helper functions to stream props using an Observable library of your choice into React. This lesson shows you how to configure Reco
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摘要:In the store marketing, for many reason, one stock's data can be incomplete: We can use 'forward fill' and 'backward fill' to fill the gap: forward fi
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摘要:Global Statistics: Common seen methods as such 1. Mean 2. Median 3. Standard deviation: the larger the number means it various a lot. 4. Sum. Rolling
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摘要:@{{user.username}} has {{followerCount}} followers button renders here Follow Unfollow
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摘要:NumPy Reference: Indexing Integer array indexing Boolean array indexing Note: The expression a < mean produces a boolean array, like:
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摘要:NumPy Reference: Indexing Integer array indexing: Select array elements with another array
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摘要:NumPy Reference: Indexing Note: Indexing starts at 0 (zero). def slicing(): a = np.random.rand(5,4) print(a) """ [[ 0.15372787 0.83347785 0.86855635 0
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摘要:NumPy Reference: Mathematical functions numpy.sum: Sum of elements - along rows, columns or all numpy.min, numpy.max, numpy.mean: Simple statistics Al
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摘要:When making a reusable component, you'll find that people often like to have the API they're most familiar with, so in this lesson we'll recreate the
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摘要:If you have state that needs to exist throughout your application, then you may find yourself passing props all over the application and even "drillin
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摘要:Attributes of numpy.ndarray: numpy.ndarray.shape: Dimensions (height, width, ...) numpy.ndarray.ndim: No. of dimensions = len(shape) numpy.ndarray.siz
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摘要:import numpy as np def test_run(): data=np.random.random((3,4)) """ [[ 0.80150549 0.96756513 0.18914514 0.85937016] [ 0.23563908 0.75685996 0.46804508 0.91735016] [ 0.7054...
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摘要:It is easy to compare the data by normalize it.
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摘要:import os import pandas as pd import matplotlib.pyplot as plt def test_run(): start_date='2017-01-01' end_data='2017-12-15' dates=pd.date_range(start_
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摘要:For example we have dataframe like this: Now we only we want to get highlighted part: We can use Dataframe.ix[] method to get date related index data
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摘要:Create an empty Data frame with date index: Now we want to load SPY.csv and get 'Adj Close' column value and copy the range (11-21, 11-28) data to the
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摘要:Install:
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摘要:Sometimes users of your component want to have more control over what the internal state is. In this lesson we'll learn how to allow users to control
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摘要:Sometimes you have common use cases that require common props to be applied to certain elements. You can collect these props into an object for users
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摘要:Object oriented classes work much like classes in other languages. Learn how to create them and use them, learn the difference between class variables
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摘要:Misunderstanding scope can cause problems in your application. Watch this lesson to learn how Python scope works and the hidden implications it presen
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摘要:Exceptions cause your application to crash. Handling them allows you to recover gracefully and keep your application running. Learn how to handle exce
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摘要:This lesson will teach you how to read the contents of an external file from Python. You will also learn how to use the python csv module to read and
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摘要:Compound component gives more rendering control to the user. The functionality of the component stays intact while how it looks and the order of the c
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摘要:A module is a function extracted to a file. This allows you to import the function and use it in any other code you may write. You’ll learn how to cre
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摘要:Parcel comes in as the new cool kid in the bundlers world. Unlike other bundlers which take lots of explicit configuration, Parcel works out of the bo
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摘要:A function's this argument is usually set implicitly, depending on how the function is called. Ordinary function calls, method calls, and constructor
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摘要:In most cases, the value of a function's this argument is determined by how the function is called. This lesson explains what thisrefers to when we ca
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摘要:Print statements will get you a long way in monitoring the behavior of your application, but logging will get your further. Learn how to implement log
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摘要:A set is an unordered collection with no duplicate items in Python. In this lesson, you will learn how to create them, and perform basic operations to
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摘要:Dictionaries may be familiar to you as hash maps. In this lesson, you will learn how to create them, get the values, and delete elements from the dict
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摘要:List comprehensions provide a concise way to create new lists, where each item is the result of an operation applied to each member of an existing lis
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摘要:isinstance("foo", str) isinstance(1, int) isinstance(4.0, float)
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摘要:For example you want to know what methods are available in Python for String, you can do : Output: Now for example, we want to see How to use 'swapcas
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摘要:Single quotes and double quotes can both be used to declare strings in Python. You can even use triple-double quotes! Learn when to use each in this l
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摘要:Python scripts can be executed by passing the script name to the python command or created as executable commands that can run stand-alone. You’ll lea
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摘要:In this lesson, you will learn what mutable and immutable objects are, and the difference between them. This understanding will help you determine whe
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摘要:If you’ve used other programming languages, you may have learned that an empty object is not the same as an object that does not exist. In this lesson
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摘要:Virtual Environments ensure that dependencies from one Python application don’t overwrite the dependencies of another application. In this lesson, you
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摘要:In this lesson we'll talk about controlling the value for inputs, textareas, and select elements. We'll see how to manage the state ourselves while st
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摘要:In this lesson we'll take a stopwatch component we built in another lesson and identify and fix a memory leak. Tow things to notice here is that: 1. t
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摘要:In this lesson we'll learn about how you can use the prop-types module to validate a custom React component's props. You can write you own PropTypes v
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摘要:import time import urllib import bs4 import requests start_url = "https://en.wikipedia.org/wiki/Special:Random" target_url = "https://en.wikipedia.org/wiki/Philosophy" def find_first_link(url): ...
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摘要:# Python's list slice syntax can be used without indices # for a few fun and useful things: # You can clear all elements from a list: >>> lst = [1, 2, 3, 4, 5] >>> del lst[:] >>> lst [] # You can r...
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摘要:https://docs.python.org/2/library/collections.html
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摘要:>>> import itertools >>> for p in itertools.permutations('ABCD'): ... print(p) ('A', 'B', 'C', 'D') ('A', 'B', 'D', 'C') ('A', 'C', 'B', 'D') ('A', 'C', 'D
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