解析目录中的html文件，并使用BeautifulSoup删除特定标记

Question

我在目录和子文件夹中有多个html文件。我想解析所有html文件（递归），并从代码特定的div（包含所有内容）中删除，再加上所有脚本和css。我想用^{id1}清除div$

HTML元素示例：

<div id="columnLeft"> <div class="box"> <h2>Book Search</h2> <div id="search"> <form action="http://www.dspguide.com/search.php" method="post"> <input type="text" name="searchfor" class="txtField" /> <input type="image" src="new/images/btn-go.png" name="Submit" value="Submit" class="button" /> <div class="clear"><!-- --></div> </form> </div> </div> <div class="box"> <h2>Download this chapter in PDF format</h2> <b><a href="CH15.PDF">Chapter15.pdf</a></b> <br /> <img src="new/images/adobe-reader.png" alt="" vspace="5" /> </div> <div class="box"> <h2>Table of contents</h2> <ul id="red" class="treeview-red"> <ul style="border-top:1px solid #aeaeeb;"><li style="border-top:1px solid #aeaeeb;"><a href="ch1.htm">1: The Breadth and Depth of DSP</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch1/1.htm">The Roots of DSP</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch1/2.htm">Telecommunications</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch1/3.htm">Audio Processing</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch1/4.htm">Echo Location</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch1/5.htm">Image Processing</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch2.htm">2: Statistics, Probability and Noise</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch2/1.htm">Signal and Graph Terminology</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch2/2.htm">Mean and Standard Deviation</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch2/3.htm">Signal vs. Underlying Process</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch2/4.htm">The Histogram, Pmf and Pdf</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch2/5.htm">The Normal Distribution</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch2/6.htm">Digital Noise Generation</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch2/7.htm">Precision and Accuracy</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch3.htm">3: ADC and DAC</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch3/1.htm">Quantization</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch3/2.htm">The Sampling Theorem</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch3/3.htm">Digital-to-Analog Conversion</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch3/4.htm">Analog Filters for Data Conversion</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch3/5.htm">Selecting The Antialias Filter</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch3/6.htm">Multirate Data Conversion</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch3/7.htm">Single Bit Data Conversion</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch4.htm">4: DSP Software</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch4/1.htm">Computer Numbers</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch4/2.htm">Fixed Point (Integers)</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch4/3.htm">Floating Point (Real Numbers)</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch4/4.htm">Number Precision</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch4/5.htm">Execution Speed: Program Language</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch4/6.htm">Execution Speed: Hardware</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch4/7.htm">Execution Speed: Programming Tips</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch5.htm">5: Linear Systems</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch5/1.htm">Signals and Systems</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch5/2.htm">Requirements for Linearity</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch5/3.htm">Static Linearity and Sinusoidal Fidelity</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch5/4.htm">Examples of Linear and Nonlinear Systems</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch5/5.htm">Special Properties of Linearity</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch5/6.htm">Superposition: the Foundation of DSP</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch5/7.htm">Common Decompositions</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch5/8.htm">Alternatives to Linearity</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch6.htm">6: Convolution</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch6/1.htm">The Delta Function and Impulse Response</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch6/2.htm">Convolution</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch6/3.htm">The Input Side Algorithm</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch6/4.htm">The Output Side Algorithm</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch6/5.htm">The Sum of Weighted Inputs</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch7.htm">7: Properties of Convolution</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch7/1.htm">Common Impulse Responses</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch7/2.htm">Mathematical Properties</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch7/3.htm">Correlation</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch7/4.htm">Speed</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch8.htm">8: The Discrete Fourier Transform</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch8/1.htm">The Family of Fourier Transform</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch8/2.htm">Notation and Format of the Real DFT</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch8/3.htm">The Frequency Domain's Independent Variable</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch8/4.htm">DFT Basis Functions</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch8/5.htm">Synthesis, Calculating the Inverse DFT</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch8/6.htm">Analysis, Calculating the DFT</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch8/7.htm">Duality</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch8/8.htm">Polar Notation</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch8/9.htm">Polar Nuisances</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch9.htm">9: Applications of the DFT</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch9/1.htm">Spectral Analysis of Signals</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch9/2.htm">Frequency Response of Systems</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch9/3.htm">Convolution via the Frequency Domain</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch10.htm">10: Fourier Transform Properties</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch10/1.htm">Linearity of the Fourier Transform</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch10/2.htm">Characteristics of the Phase</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch10/3.htm">Periodic Nature of the DFT</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch10/4.htm">Compression and Expansion, Multirate methods</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch10/5.htm">Multiplying Signals (Amplitude Modulation)</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch10/6.htm">The Discrete Time Fourier Transform</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch10/7.htm">Parseval's Relation</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch11.htm">11: Fourier Transform Pairs</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch11/1.htm">Delta Function Pairs</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch11/2.htm">The Sinc Function</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch11/3.htm">Other Transform Pairs</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch11/4.htm">Gibbs Effect</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch11/5.htm">Harmonics</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch11/6.htm">Chirp Signals</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch12.htm">12: The Fast Fourier Transform</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch12/1.htm">Real DFT Using the Complex DFT</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch12/2.htm">How the FFT works</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch12/3.htm">FFT Programs</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch12/4.htm">Speed and Precision Comparisons</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch12/5.htm">Further Speed Increases</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch13.htm">13: Continuous Signal Processing</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch13/1.htm">The Delta Function</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch13/2.htm">Convolution</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch13/3.htm">The Fourier Transform</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch13/4.htm">The Fourier Series</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch14.htm">14: Introduction to Digital Filters</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch14/1.htm">Filter Basics</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch14/2.htm">How Information is Represented in Signals</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch14/3.htm">Time Domain Parameters</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch14/4.htm">Frequency Domain Parameters</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch14/5.htm">High-Pass, Band-Pass and Band-Reject Filters</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch14/6.htm">Filter Classification</a></li></ul></li><li class="open" style="border-top:1px solid #aeaeeb;"><a href="ch15.htm" style="color:#b4b4e9;">15: Moving Average Filters</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch15/1.htm">Implementation by Convolution</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch15/2.htm">Noise Reduction vs. Step Response</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch15/3.htm">Frequency Response</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch15/4.htm">Relatives of the Moving Average Filter</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch15/5.htm">Recursive Implementation</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch16.htm">16: Windowed-Sinc Filters</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch16/1.htm">Strategy of the Windowed-Sinc</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch16/2.htm">Designing the Filter</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch16/3.htm">Examples of Windowed-Sinc Filters</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch16/4.htm">Pushing it to the Limit</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch17.htm">17: Custom Filters</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch17/1.htm">Arbitrary Frequency Response</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch17/2.htm">Deconvolution</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch17/3.htm">Optimal Filters</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch18.htm">18: FFT Convolution</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch18/1.htm">The Overlap-Add Method</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch18/2.htm">FFT Convolution</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch18/3.htm">Speed Improvements</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch19.htm">19: Recursive Filters</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch19/1.htm">The Recursive Method</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch19/2.htm">Single Pole Recursive Filters</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch19/3.htm">Narrow-band Filters</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch19/4.htm">Phase Response</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch19/5.htm">Using Integers</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch20.htm">20: Chebyshev Filters</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch20/1.htm">The Chebyshev and Butterworth Responses</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch20/2.htm">Designing the Filter</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch20/3.htm">Step Response Overshoot</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch20/4.htm">Stability</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch21.htm">21: Filter Comparison</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch21/1.htm">Match #1: Analog vs. Digital Filters</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch21/2.htm">Match #2: Windowed-Sinc vs. Chebyshev</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch21/3.htm">Match #3: Moving Average vs. Single Pole</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch22.htm">22: Audio Processing</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch22/1.htm">Human Hearing</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch22/2.htm">Timbre</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch22/3.htm">Sound Quality vs. Data Rate</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch22/4.htm">High Fidelity Audio</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch22/5.htm">Companding</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch22/6.htm">Speech Synthesis and Recognition</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch22/7.htm">Nonlinear Audio Processing</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch23.htm">23: Image Formation & Display</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch23/1.htm">Digital Image Structure</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch23/2.htm">Cameras and Eyes</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch23/3.htm">Television Video Signals</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch23/4.htm">Other Image Acquisition and Display</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch23/5.htm">Brightness and Contrast Adjustments</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch23/6.htm">Grayscale Transforms</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch23/7.htm">Warping</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch24.htm">24: Linear Image Processing</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch24/1.htm">Convolution</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch24/2.htm">3x3 Edge Modification</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch24/3.htm">Convolution by Separability</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch24/4.htm">Example of a Large PSF: Illumination Flattening</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch24/5.htm">Fourier Image Analysis</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch24/6.htm">FFT Convolution</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch24/7.htm">A Closer Look at Image Convolution</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch25.htm">25: Special Imaging Techniques</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch25/1.htm">Spatial Resolution</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch25/2.htm">Sample Spacing and Sampling Aperture</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch25/3.htm">Signal-to-Noise Ratio</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch25/4.htm">Morphological Image Processing</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch25/5.htm">Computed Tomography</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch26.htm">26: Neural Networks (and more!)</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch26/1.htm">Target Detection</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch26/2.htm">Neural Network Architecture</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch26/3.htm">Why Does it Work?</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch26/4.htm">Training the Neural Network</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch26/5.htm">Evaluating the Results</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch26/6.htm">Recursive Filter Design</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch27.htm">27: Data Compression</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch27/1.htm">Data Compression Strategies</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch27/2.htm">Run-Length Encoding</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch27/3.htm">Huffman Encoding</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch27/4.htm">Delta Encoding</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch27/5.htm">LZW Compression</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch27/6.htm">JPEG (Transform Compression)</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch27/7.htm">MPEG</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch28.htm">28: Digital Signal Processors</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch28/1.htm">How DSPs are Different from Other Microprocessors</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch28/2.htm">Circular Buffering</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch28/3.htm">Architecture of the Digital Signal Processor</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch28/4.htm">Fixed versus Floating Point</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch28/5.htm">C versus Assembly</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch28/6.htm">How Fast are DSPs?</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch28/7.htm">The Digital Signal Processor Market</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch29.htm">29: Getting Started with DSPs</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch29/1.htm">The ADSP-2106x family</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch29/2.htm">The SHARC EZ-KIT Lite</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch29/3.htm">Design Example: An FIR Audio Filter</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch29/4.htm">Analog Measurements on a DSP System</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch29/5.htm">Another Look at Fixed versus Floating Point</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch29/6.htm">Advanced Software Tools</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch30.htm">30: Complex Numbers</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch30/1.htm">The Complex Number System</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch30/2.htm">Polar Notation</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch30/3.htm">Using Complex Numbers by Substitution</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch30/4.htm">Complex Representation of Sinusoids</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch30/5.htm">Complex Representation of Systems</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch30/6.htm">Electrical Circuit Analysis</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch31.htm">31: The Complex Fourier Transform</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch31/1.htm">The Real DFT</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch31/2.htm">Mathematical Equivalence</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch31/3.htm">The Complex DFT</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch31/4.htm">The Family of Fourier Transforms</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch31/5.htm">Why the Complex Fourier Transform is Used</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch32.htm">32: The Laplace Transform</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch32/1.htm">The Nature of the s-Domain</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch32/2.htm">Strategy of the Laplace Transform</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch32/3.htm">Analysis of Electric Circuits</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch32/4.htm">The Importance of Poles and Zeros</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch32/5.htm">Filter Design in the s-Domain</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch33.htm">33: The z-Transform</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch33/1.htm">The Nature of the z-Domain</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch33/2.htm">Analysis of Recursive Systems</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch33/3.htm">Cascade and Parallel Stages</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch33/4.htm">Spectral Inversion</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch33/5.htm">Gain Changes</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch33/6.htm">Chebyshev-Butterworth Filter Design</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch33/7.htm">The Best and Worst of DSP</a></li></ul></li><li style="border-top:1px solid #aeaeeb;"><a href="ch34.htm">34: Explaining Benford's Law</a><ul><li style="border-top:1px solid #aeaeeb;"><a href="ch34/1.htm">Frank Benford's Discovery</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch34/2.htm">Homomorphic Processing</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch34/3.htm">The Ones Scaling Test</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch34/4.htm">Writing Benford's Law as a Convolution</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch34/5.htm">Solving in the Frequency Domain</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch34/6.htm">Solving Mystery #1</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch34/7.htm">Solving Mystery #2</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch34/8.htm">More on Following Benford's law</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch34/9.htm">Analysis of the Log-Normal Distribution</a></li><li style="border-top:1px solid #aeaeeb;"><a href="ch34/10.htm">The Power of Signal Processing</a></li></ul></li> </ul> </ul> </div> <div class="box"> <h2>How to order your own hardcover copy</h2> Wouldn't you rather have a bound book instead of 640 loose pages?<br /> Your laser printer will thank you!<br /> <b>Order from <a href="http://www.amazon.com/Scientist-Engineers-Digital-Signal-Processing/dp/0966017633/ref=pd_bxgy_b_img_a">Amazon.com</a>.</b> </div> </div> <!-- --> <div id="columnRight"> <div id="adbox"> </div> <h2>Chapter 15: Moving Average Filters</h2><p>The moving average is the most common filter in DSP, mainly because it is the easiest digital filter to understand and use. In spite of its simplicity, the moving average filter is <i>optimal</i> for a common task: reducing random noise while retaining a sharp step response. This makes it the premier filter for time domain encoded signals. However, the moving average is the <i>worst</i> filter for frequency domain encoded signals, with little ability to separate one band of frequencies from another. Relatives of the moving average filter include the Gaussian, Blackman, and multiple-pass moving average. These have slightly better performance in the frequency domain, at the expense of increased computation time. </p><ul><li><a href="ch15/1.htm">Implementation by Convolution</a></li><li><a href="ch15/2.htm">Noise Reduction vs. Step Response</a></li><li><a href="ch15/3.htm">Frequency Response</a></li><li><a href="ch15/4.htm">Relatives of the Moving Average Filter</a></li><li><a href="ch15/5.htm">Recursive Implementation</a></li></ul> </div> <div class="clear"><!-- --></div> </div> </div>

Answer 1

您可以使用htql，例如：

html = """
<title>Moving Average Filters</title>
<link href="new/css/default.css" rel="stylesheet" type="text/css" />

<script type='text/javascript' src='new/js/jquery-1.5.js'></script>
<script type='text/javascript' src='new/js/jquery.droppy.js'></script>
<link rel="stylesheet" href="new/css/droppy.css" type="text/css" />

<div id="footer">
    <a href="index.html">Home</a> | <a href="pdfbook.htm">The Book by Chapters</a> | <a href="about.htm">About the Book</a> | <a href="swsmith.htm">Steven W. Smith</a> | <a href="http://www.dsprelated.com/blogs-1/nf/Steve_Smith.php">Blog</a> | <a href="http://www.dspguide.com/contact.htm">Contact</a>
    <br />
    Copyright 1997-2011 by California Technical Publishing
</div>
"""

import htql
x=htql.query(html, "<script> &delete <div norecur (id='footer')>&delete")[0][0]

你会得到：

>>> x
'\n<title>Moving Average Filters</title>\n<link href="new/css/default.css" rel="stylesheet" type="text/css" />\n\n\n\n<link rel="stylesheet" href="new/css/droppy.css" type="text/css" />\n\n\n'

要转换目录dir1中的html文件并将其保存到目录dir2，可以创建如下函数：

import htql
def convert(filename, dir1, dir2): 
  html = open(os.path.join(dir1, filename), 'r').read()
  x=htql.query(html, "<script> &delete <div norecur (id='footer')>&delete")[0][0]
  open(os.path.join(dir2, filename), 'w').write(x)

然后，要转换dir1中的所有文件，可以使用循环：

import os
for filename in os.listdir(dir1): 
  if filename.endswith('.html'):
    convert(filename, dir1, dir2)

Answer 2

在python中，可以在for循环中使用。 示例：（对于bs中的i）： i、 正文（）