title
Python Tutorial: File Objects - Reading and Writing to Files

description
In this Python Tutorial, we will be learning how to read and write to files. You will likely come into contact with file objects at some point while using Python, so knowing how to read and write from them is extremely important. We will learn how to read and write from simple text files, open multiple files at once, and also how to copy image binary files. Let's get started. The code from this video can be found at: https://github.com/CoreyMSchafer/code_snippets/tree/master/Python-Files Read more about opening in binary mode here: https://docs.python.org/3/library/functions.html#open ✅ Support My Channel Through Patreon: https://www.patreon.com/coreyms ✅ Become a Channel Member: https://www.youtube.com/channel/UCCezIgC97PvUuR4_gbFUs5g/join ✅ One-Time Contribution Through PayPal: https://goo.gl/649HFY ✅ Cryptocurrency Donations: Bitcoin Wallet - 3MPH8oY2EAgbLVy7RBMinwcBntggi7qeG3 Ethereum Wallet - 0x151649418616068fB46C3598083817101d3bCD33 Litecoin Wallet - MPvEBY5fxGkmPQgocfJbxP6EmTo5UUXMot ✅ Corey's Public Amazon Wishlist http://a.co/inIyro1 ✅ Equipment I Use and Books I Recommend: https://www.amazon.com/shop/coreyschafer ▶️ You Can Find Me On: My Website - http://coreyms.com/ My Second Channel - https://www.youtube.com/c/coreymschafer Facebook - https://www.facebook.com/CoreyMSchafer Twitter - https://twitter.com/CoreyMSchafer Instagram - https://www.instagram.com/coreymschafer/ #Python

detail
{'title': 'Python Tutorial: File Objects - Reading and Writing to Files', 'heatmap': [{'end': 474.262, 'start': 453.907, 'weight': 0.72}, {'end': 1195.335, 'start': 1178.533, 'weight': 1}], 'summary': 'This python tutorial on file objects covers opening and reading plain text files, emphasizing the use of context managers for proper file handling. it also explains memory-efficient methods for reading large files, file operations including seek and different modes, and working with image files in binary mode.', 'chapters': [{'end': 252.122, 'segs': [{'end': 57.397, 'src': 'embed', 'start': 19.329, 'weight': 0, 'content': [{'end': 20.951, 'text': "Okay, so let's go ahead and dive in.", 'start': 19.329, 'duration': 1.622}, {'end': 25.135, 'text': 'So to get a file object, we can use the built-in open command.', 'start': 21.351, 'duration': 3.784}, {'end': 31.621, 'text': 'So I have a file here called test.txt in the same directory as my Python file.', 'start': 25.495, 'duration': 6.126}, {'end': 36.967, 'text': "Now, if I open this file, we can see that it's just a plain text file with multiple lines.", 'start': 32.061, 'duration': 4.906}, {'end': 40.971, 'text': "So let's see how we can open and read this file from within Python.", 'start': 37.307, 'duration': 3.664}, {'end': 45.893, 'text': "Now, the way I'm going to open up the file right now isn't the way that it's normally recommended.", 'start': 41.471, 'duration': 4.422}, {'end': 50.974, 'text': "It's usually recommended to use a context manager, which I'll show you here in just a second.", 'start': 46.433, 'duration': 4.541}, {'end': 57.397, 'text': 'But to show you why a context manager is useful, let me first show you this method for opening files first.', 'start': 51.375, 'duration': 6.022}], 'summary': 'Using open command to get file object in python for test.txt.', 'duration': 38.068, 'max_score': 19.329, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/Uh2ebFW8OYM/pics/Uh2ebFW8OYM19329.jpg'}, {'end': 103.985, 'src': 'embed', 'start': 80.115, 'weight': 1, 'content': [{'end': 87.243, 'text': 'But if you want to learn more about how paths work, then we touch on that a little bit in the tutorial I did on the OS module.', 'start': 80.115, 'duration': 7.128}, {'end': 96.844, 'text': 'Okay, so the open command here allows us to specify whether we want to open this file for reading, writing, appending, or reading and writing.', 'start': 87.782, 'duration': 9.062}, {'end': 103.985, 'text': "Now, if we don't specify anything, then it defaults to opening the file for reading, but I usually like to be explicit here.", 'start': 97.484, 'duration': 6.501}], 'summary': 'The open command allows specifying file access modes, defaulting to reading.', 'duration': 23.87, 'max_score': 80.115, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/Uh2ebFW8OYM/pics/Uh2ebFW8OYM80115.jpg'}, {'end': 229.256, 'src': 'embed', 'start': 205.747, 'weight': 2, 'content': [{'end': 213.73, 'text': 'then you can end up with leaks that cause you to run over the maximum allowed file descriptors on your system and your applications could throw an error.', 'start': 205.747, 'duration': 7.983}, {'end': 217.691, 'text': "So it's always important to make sure that you close the files that you open.", 'start': 214.15, 'duration': 3.541}, {'end': 225.555, 'text': "So in order to use a context manager, then it's kind of similar, but we can do this using the with keyword.", 'start': 218.152, 'duration': 7.403}, {'end': 229.256, 'text': "So we can say with, and then I'm just going to copy all of this.", 'start': 225.895, 'duration': 3.361}], 'summary': "Leaving files open can cause system errors. use context manager with 'with' keyword to ensure file closure.", 'duration': 23.509, 'max_score': 205.747, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/Uh2ebFW8OYM/pics/Uh2ebFW8OYM205747.jpg'}], 'start': 0.289, 'title': 'Working with file objects in python', 'summary': 'Discusses the importance of properly interacting with file objects, demonstrating how to open and read a plain text file using the built-in open command, with the recommendation to use a context manager for better practice. it also covers specifying file paths, file modes, and the importance of closing files to avoid system errors and leaks.', 'chapters': [{'end': 57.397, 'start': 0.289, 'title': 'Working with file objects in python', 'summary': 'Discusses working with file objects in python, emphasizing the importance of properly interacting with file objects and demonstrating how to open and read a plain text file using the built-in open command, with the recommendation to use a context manager for better practice.', 'duration': 57.108, 'highlights': ['The importance of properly interacting with file objects Emphasizes the significance of knowing how to properly interact with file objects, as it is a valuable skill for Python desktop or web application development.', "Demonstrating how to open and read a plain text file using the built-in open command Illustrates the process of opening and reading a plain text file, 'test.txt,' using the built-in open command in Python.", 'Recommendation to use a context manager for better practice Highlights the recommendation to use a context manager for opening files, emphasizing its usefulness and better practice over alternative methods.']}, {'end': 252.122, 'start': 57.817, 'title': 'Working with files in python', 'summary': 'Covers opening and reading files in python, including specifying file paths, file modes, file closing, and using a context manager, emphasizing the importance of closing files to avoid system errors and leaks.', 'duration': 194.305, 'highlights': ['The open command allows us to specify whether we want to open a file for reading, writing, appending, or reading and writing, with default as reading mode, and explicit mode declaration recommended.', 'Explicitly closing files is crucial to prevent system errors and leaks, which can occur if the maximum allowed file descriptors are exceeded.', "Using a context manager with the 'with' keyword is recommended for most use cases to avoid the need to explicitly close files and ensure proper file handling.", "The chapter emphasizes the importance of closing files to avoid running over the maximum allowed file descriptors and potential system errors, highlighting the benefits of using a context manager with the 'with' keyword.", 'The tutorial briefly mentions the usage of the OS module for working with file paths, providing a reference for further learning.']}], 'duration': 251.833, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/Uh2ebFW8OYM/pics/Uh2ebFW8OYM289.jpg', 'highlights': ["Demonstrating how to open and read a plain text file using the built-in open command Illustrates the process of opening and reading a plain text file, 'test.txt,' using the built-in open command in Python.", 'The open command allows us to specify whether we want to open a file for reading, writing, appending, or reading and writing, with default as reading mode, and explicit mode declaration recommended.', "Using a context manager with the 'with' keyword is recommended for most use cases to avoid the need to explicitly close files and ensure proper file handling.", "The chapter emphasizes the importance of closing files to avoid running over the maximum allowed file descriptors and potential system errors, highlighting the benefits of using a context manager with the 'with' keyword.", 'Recommendation to use a context manager for better practice Highlights the recommendation to use a context manager for opening files, emphasizing its usefulness and better practice over alternative methods.']}, {'end': 467.617, 'segs': [{'end': 279.778, 'src': 'embed', 'start': 252.582, 'weight': 0, 'content': [{'end': 257.826, 'text': 'But the benefit of these context managers is that they allow us to work with files from within this block.', 'start': 252.582, 'duration': 5.244}, {'end': 262.79, 'text': "And after we exit that block of code, it'll automatically close the file for us.", 'start': 258.207, 'duration': 4.583}, {'end': 267.014, 'text': "So we don't have to worry about whether or not we add in these closes here.", 'start': 262.85, 'duration': 4.164}, {'end': 272.278, 'text': 'Now, this will also close the file if there are any exceptions that are thrown or anything like that.', 'start': 267.454, 'duration': 4.824}, {'end': 276.456, 'text': "So that's why using these context managers are considered a best practice.", 'start': 272.714, 'duration': 3.742}, {'end': 279.778, 'text': 'And it just automatically takes care of all that cleanup for us.', 'start': 276.896, 'duration': 2.882}], 'summary': "Context managers automatically close files, even during exceptions. it's a best practice.", 'duration': 27.196, 'max_score': 252.582, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/Uh2ebFW8OYM/pics/Uh2ebFW8OYM252582.jpg'}, {'end': 361.793, 'src': 'embed', 'start': 318.084, 'weight': 1, 'content': [{'end': 322.125, 'text': 'Like, if I try to read the contents from the file and print that out,', 'start': 318.084, 'duration': 4.041}, {'end': 328.468, 'text': 'then you can see that it throws a value error here and it says IO operation on a closed file.', 'start': 322.125, 'duration': 6.343}, {'end': 334.793, 'text': "So for what we want, we're going to have to work with this file from within this context manager.", 'start': 328.968, 'duration': 5.825}, {'end': 340.158, 'text': "And for the rest of the video, I'll be using these context managers to work with files since it's a good practice.", 'start': 335.354, 'duration': 4.804}, {'end': 345.803, 'text': "But I wanted to show you the other way first in case you see it in examples or wondered why I wasn't doing it that way.", 'start': 340.438, 'duration': 5.365}, {'end': 347.984, 'text': 'Okay, so back to our file.', 'start': 346.423, 'duration': 1.561}, {'end': 352.467, 'text': 'So we just tried to read the contents from the closed file and got our error.', 'start': 348.364, 'duration': 4.103}, {'end': 357.49, 'text': "But let's look at how we can read the contents from the file from here within our context manager.", 'start': 352.867, 'duration': 4.623}, {'end': 361.793, 'text': "So let's create a variable called F underscore contents.", 'start': 357.97, 'duration': 3.823}], 'summary': 'Using context managers to work with files is a good practice.', 'duration': 43.709, 'max_score': 318.084, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/Uh2ebFW8OYM/pics/Uh2ebFW8OYM318084.jpg'}, {'end': 447.823, 'src': 'embed', 'start': 405.466, 'weight': 3, 'content': [{'end': 414.048, 'text': 'and if I print this out then you can see that we get a list of all of the lines in the file and it looks a little weird because we have our new line characters in there.', 'start': 405.466, 'duration': 8.582}, {'end': 421.77, 'text': 'but if we look through this list, then it actually gets every line of the file as a different element of that list.', 'start': 414.048, 'duration': 7.722}, {'end': 427.032, 'text': 'Now, instead of f.readlines, I could do f.readline.', 'start': 422.31, 'duration': 4.722}, {'end': 432.975, 'text': 'And if I save that and run it, then you can see that readline grabbed the first line of our file.', 'start': 427.172, 'duration': 5.803}, {'end': 438.277, 'text': 'Now, every time that we run f.readline, it gets the next line in our file.', 'start': 433.415, 'duration': 4.862}, {'end': 444.08, 'text': 'So if I was to copy all of this and then do it again and run that.', 'start': 438.697, 'duration': 5.383}, {'end': 447.823, 'text': 'Now you can see that it got the first and the second lines from the file.', 'start': 444.521, 'duration': 3.302}], 'summary': 'Demonstration of reading lines from a file using python, showing usage of f.readlines and f.readline, retrieving all lines and individual lines respectively.', 'duration': 42.357, 'max_score': 405.466, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/Uh2ebFW8OYM/pics/Uh2ebFW8OYM405466.jpg'}], 'start': 252.582, 'title': 'Python file handling and reading', 'summary': 'Covers the benefits of using context managers for file handling in python, demonstrating their automatic file closing and cleanup, and explains reading file contents and printing lines, promoting best practices for efficient file operations.', 'chapters': [{'end': 295.567, 'start': 252.582, 'title': 'Python context managers and file handling', 'summary': 'Explains the benefits of using context managers in python, highlighting how they automatically handle file closing and cleanup, even in the event of exceptions, promoting it as a best practice.', 'duration': 42.985, 'highlights': ['Context managers automatically handle file closing and cleanup, even in the event of exceptions, promoting it as a best practice. Using context managers automatically closes the file, even in the event of exceptions, eliminating the need for explicit close statements.', 'Access to the F variable within the context manager. Access to the F variable within the context manager is available, providing flexibility and control within the block.']}, {'end': 405.466, 'start': 296.047, 'title': 'Working with file contents in python', 'summary': 'Discusses the use of context managers to work with files, demonstrating how to read file contents within the context manager and highlighting the available methods for reading file contents instead of f dot read.', 'duration': 109.419, 'highlights': ['Context managers are used to work with files, with the demonstration of reading file contents within the context manager being a good practice', 'The closed method on the file object returns true when the file is closed, and attempting to read from a closed file throws a value error', 'Demonstrates how to read the contents of a file within the context manager using F dot read, and the use of a variable to hold the contents of the file', 'Explains the need for alternative methods for reading file contents, especially when dealing with extremely large files and a mention of the f.readlines method']}, {'end': 467.617, 'start': 405.466, 'title': 'Reading file and printing lines', 'summary': 'Explains how to read and print lines from a file using f.readlines and f.readline, demonstrating the retrieval of lines and the removal of new line characters in the output.', 'duration': 62.151, 'highlights': ['The chapter demonstrates the use of f.readlines to retrieve all lines in the file as elements of a list, including the presence of new line characters in the output.', 'It also illustrates the usage of f.readline to grab the first line of the file and subsequently get the next line each time it is called.', 'Additionally, it showcases how to remove the extra new line character in the printed output by passing an empty string to the end of the print statement.']}], 'duration': 215.035, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/Uh2ebFW8OYM/pics/Uh2ebFW8OYM252582.jpg', 'highlights': ['Context managers automatically handle file closing and cleanup, even in the event of exceptions, promoting it as a best practice. Using context managers automatically closes the file, even in the event of exceptions, eliminating the need for explicit close statements.', 'The closed method on the file object returns true when the file is closed, and attempting to read from a closed file throws a value error.', 'Demonstrates how to read the contents of a file within the context manager using F dot read, and the use of a variable to hold the contents of the file.', 'The chapter demonstrates the use of f.readlines to retrieve all lines in the file as elements of a list, including the presence of new line characters in the output.', 'It also illustrates the usage of f.readline to grab the first line of the file and subsequently get the next line each time it is called.']}, {'end': 828.431, 'segs': [{'end': 511.83, 'src': 'embed', 'start': 483.809, 'weight': 0, 'content': [{'end': 492.615, 'text': "So what we're going to do here is instead of using readline or readlines, we can simply iterate over the lines in a file by saying for..", 'start': 483.809, 'duration': 8.806}, {'end': 499.884, 'text': 'Oh, let me go to a new line here for line in F.', 'start': 494.861, 'duration': 5.023}, {'end': 502.625, 'text': 'And then from here we can just print that line.', 'start': 499.884, 'duration': 2.741}, {'end': 506.167, 'text': "So I'm going to copy that and save that.", 'start': 502.665, 'duration': 3.502}, {'end': 511.83, 'text': 'So now let me go ahead and comment out these lines and run this iteration over the lines.', 'start': 506.607, 'duration': 5.223}], 'summary': 'Iterating over lines in a file using for loop instead of readline or readlines.', 'duration': 28.021, 'max_score': 483.809, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/Uh2ebFW8OYM/pics/Uh2ebFW8OYM483809.jpg'}, {'end': 589.822, 'src': 'embed', 'start': 555.773, 'weight': 3, 'content': [{'end': 558.918, 'text': 'So if I run that, you can see that we got the exact same thing.', 'start': 555.773, 'duration': 3.145}, {'end': 566.828, 'text': 'But with f.read, we can actually specify the amount of data that we want to read at a time by passing in the size as an argument.', 'start': 559.378, 'duration': 7.45}, {'end': 573.592, 'text': 'So if I pass in a 100 to our read method and then print this out,', 'start': 567.208, 'duration': 6.384}, {'end': 580.096, 'text': 'you can see that it printed out the first 100 characters of our file instead of printing the whole thing all at once.', 'start': 573.592, 'duration': 6.504}, {'end': 589.822, 'text': 'Now, if I was to copy this and run this again, then you can see that it printed out the rest of the file,', 'start': 580.576, 'duration': 9.246}], 'summary': 'F.read method can specify amount of data to read, e.g., 100 prints first 100 characters.', 'duration': 34.049, 'max_score': 555.773, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/Uh2ebFW8OYM/pics/Uh2ebFW8OYM555773.jpg'}, {'end': 803.617, 'src': 'embed', 'start': 773.655, 'weight': 4, 'content': [{'end': 774.759, 'text': "and we'll print out f.tel.", 'start': 773.655, 'duration': 1.104}, {'end': 781.948, 'text': 'So if I go ahead and run that, you can see the f.tel returned 10.', 'start': 777.506, 'duration': 4.442}, {'end': 786.15, 'text': "So it's saying that we're currently at the 10th position in the file,", 'start': 781.948, 'duration': 4.202}, {'end': 794.553, 'text': "and that's because we've already read in 10 characters here and we can manipulate our current position using the seek method.", 'start': 786.15, 'duration': 8.403}, {'end': 803.617, 'text': 'So to show an example of this, let me print the first 20 characters of the file by running f.read twice.', 'start': 795.073, 'duration': 8.544}], 'summary': 'Using file operations, f.tel returns 10, showing current position in the file.', 'duration': 29.962, 'max_score': 773.655, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/Uh2ebFW8OYM/pics/Uh2ebFW8OYM773655.jpg'}], 'start': 468.217, 'title': 'Efficient file reading', 'summary': 'Discusses memory-efficient methods of reading large files by iterating over lines, avoiding memory issues and improving efficiency. it also demonstrates reading files in chunks for better data control, with examples using 100 and 10 characters, and manipulation of file position using f.tell and seek method.', 'chapters': [{'end': 529.22, 'start': 468.217, 'title': 'Reading large files efficiently', 'summary': "Discusses a more memory-efficient method of reading large files by iterating over the lines using 'for line in f', which avoids the risk of running out of memory and improves efficiency by obtaining one line at a time.", 'duration': 61.003, 'highlights': ["Iterating over the lines in a file using 'for line in F' is a memory-efficient method of reading large files. This method avoids the risk of running out of memory when reading an extremely large file and improves efficiency by obtaining one line at a time.", "Using 'for line in F' allows for efficient reading of large files without the risk of a memory issue. This approach eliminates the concern of running out of memory while reading the entire file at once, thus improving the efficiency of file reading.", "Reading large files using 'for line in F' is memory-efficient and avoids the risk of memory issues. By iterating over the lines in a file, this method ensures that the entire file is not read into memory at once, thus mitigating the risk of memory-related problems."]}, {'end': 828.431, 'start': 529.74, 'title': 'Reading files in chunks', 'summary': 'Demonstrates how to read files in chunks, allowing for more control over the amount of data read at a time, with an example using 100 characters and then 10 characters, and also shows how to manipulate the current position in the file using f.tell and the seek method.', 'duration': 298.691, 'highlights': ['It explains how to read files in chunks, showing an example using 100 characters and then 10 characters. The chapter demonstrates using f.read to specify the amount of data to read at a time, with an example using 100 characters and then 10 characters.', 'It shows how to manipulate the current position in the file using f.tell and the seek method. The chapter explains how to use f.tell to determine the current position in the file and how to manipulate it using the seek method.']}], 'duration': 360.214, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/Uh2ebFW8OYM/pics/Uh2ebFW8OYM468217.jpg', 'highlights': ["Iterating over the lines in a file using 'for line in F' is a memory-efficient method of reading large files.", "Using 'for line in F' allows for efficient reading of large files without the risk of a memory issue.", "Reading large files using 'for line in F' is memory-efficient and avoids the risk of memory issues.", 'It explains how to read files in chunks, showing an example using 100 characters and then 10 characters.', 'It shows how to manipulate the current position in the file using f.tell and the seek method.']}, {'end': 1465.249, 'segs': [{'end': 951.686, 'src': 'embed', 'start': 900.538, 'weight': 0, 'content': [{'end': 905.159, 'text': "So I'll do an f.write and I'll just do an f.write of test.", 'start': 900.538, 'duration': 4.621}, {'end': 909.26, 'text': "I'm going to go ahead and get rid of that while loop also and save that.", 'start': 905.4, 'duration': 3.86}, {'end': 917.782, 'text': 'So you see when I have a file open in read mode and try to write that we get an error that says that this is not writable.', 'start': 910.081, 'duration': 7.701}, {'end': 920.203, 'text': 'So we have to have the file open in write mode.', 'start': 917.922, 'duration': 2.281}, {'end': 923.726, 'text': 'So now back up here within our open statement.', 'start': 920.743, 'duration': 2.983}, {'end': 932.436, 'text': "Let's create a new file called test2.txt and instead of reading we are going to write to it.", 'start': 924.147, 'duration': 8.289}, {'end': 938.122, 'text': 'Now in order to do that we can just say a lowercase w instead of that lowercase r.', 'start': 932.977, 'duration': 5.145}, {'end': 943.224, 'text': "Now you can see over here in our directory that we don't have a test2.txt yet.", 'start': 938.743, 'duration': 4.481}, {'end': 948.265, 'text': "Now if the file doesn't exist already, then this will go ahead and create it.", 'start': 943.604, 'duration': 4.661}, {'end': 951.686, 'text': 'Now if the file does exist, then it will overwrite it.', 'start': 948.625, 'duration': 3.061}], 'summary': "Demonstration of writing to a file in python, creating and overwriting files, using 'w' mode.", 'duration': 51.148, 'max_score': 900.538, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/Uh2ebFW8OYM/pics/Uh2ebFW8OYM900538.jpg'}, {'end': 1050.237, 'src': 'embed', 'start': 1022.304, 'weight': 1, 'content': [{'end': 1027.627, 'text': 'Now you can actually use seek when writing files also to set the position back to the beginning of the file.', 'start': 1022.304, 'duration': 5.323}, {'end': 1035.369, 'text': 'And we can do this if I go back here between these two write statements and I was to do an f.seek of zero.', 'start': 1028.186, 'duration': 7.183}, {'end': 1042.273, 'text': 'Now if I run this, then you can see that the second test overwrote the first one.', 'start': 1035.849, 'duration': 6.424}, {'end': 1050.237, 'text': "So seek can get a little confusing for file write because it doesn't overwrite everything, only what it needs to overwrite.", 'start': 1042.634, 'duration': 7.603}], 'summary': 'Using seek to set file position back to beginning, allowing overwriting specific content.', 'duration': 27.933, 'max_score': 1022.304, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/Uh2ebFW8OYM/pics/Uh2ebFW8OYM1022304.jpg'}, {'end': 1221.014, 'src': 'heatmap', 'start': 1178.533, 'weight': 2, 'content': [{'end': 1183.496, 'text': "Now to do this, it's just as easy as saying for line in copy.", 'start': 1178.533, 'duration': 4.963}, {'end': 1192.953, 'text': 'rf. we want to do a wf.write that line.', 'start': 1184.462, 'duration': 8.491}, {'end': 1195.335, 'text': "okay, so now let's walk over this one more time.", 'start': 1192.953, 'duration': 2.382}, {'end': 1201.9, 'text': "so we have our original file opened and we're reading from that file and we have a file that doesn't exist yet.", 'start': 1195.335, 'duration': 6.565}, {'end': 1212.587, 'text': "that's our copy, and we're writing to that file and we're saying for each line in our original file write that line to WF,", 'start': 1201.9, 'duration': 10.687}, {'end': 1214.869, 'text': 'which is the file that we are copying to.', 'start': 1212.587, 'duration': 2.282}, {'end': 1221.014, 'text': 'and If I go ahead and run that, then you can see that it created this testcopy.txt file.', 'start': 1214.869, 'duration': 6.145}], 'summary': 'Using python, a file is copied by reading from an original file and writing to a new file, resulting in the creation of testcopy.txt.', 'duration': 42.481, 'max_score': 1178.533, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/Uh2ebFW8OYM/pics/Uh2ebFW8OYM1178533.jpg'}, {'end': 1329.496, 'src': 'embed', 'start': 1301.041, 'weight': 5, 'content': [{'end': 1312.988, 'text': 'But for this case, in order to work with these pictures, to use binary mode, we can just append a B to our read R here and our write W there.', 'start': 1301.041, 'duration': 11.947}, {'end': 1321.272, 'text': 'So now with that one simple change, if I save that and now run it, then you can see that we do have this copied picture file here.', 'start': 1313.448, 'duration': 7.824}, {'end': 1329.496, 'text': 'And if I go over to Finder, then you can see that that file copied exactly the way that the original is.', 'start': 1321.673, 'duration': 7.823}], 'summary': 'Using binary mode, appending a b to the read r and write w, successfully copied a picture file.', 'duration': 28.455, 'max_score': 1301.041, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/Uh2ebFW8OYM/pics/Uh2ebFW8OYM1301041.jpg'}, {'end': 1407.075, 'src': 'embed', 'start': 1379.501, 'weight': 3, 'content': [{'end': 1386.744, 'text': "So now let's create a loop that will write these chunks to our copy until there's nothing left to read from the original.", 'start': 1379.501, 'duration': 7.243}, {'end': 1391.507, 'text': 'And if you remember from earlier to do this, we can do a while loop.', 'start': 1387.165, 'duration': 4.342}, {'end': 1399.071, 'text': 'And while the length of this chunk here is greater then 0.', 'start': 1391.987, 'duration': 7.084}, {'end': 1403.713, 'text': 'Then we want to take our copy file and write that chunk to it.', 'start': 1399.071, 'duration': 4.642}, {'end': 1407.075, 'text': "So I'm going to write this chunk to our copy.", 'start': 1404.033, 'duration': 3.042}], 'summary': 'Create a loop to write chunks to copy file until original is fully read.', 'duration': 27.574, 'max_score': 1379.501, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/Uh2ebFW8OYM/pics/Uh2ebFW8OYM1379501.jpg'}], 'start': 828.872, 'title': 'File operations in python', 'summary': "Covers file reading and writing basics, including using f.seek to change the file position, differentiating write and read modes, and the behavior of seek when writing to files. it also discusses using file objects in python to copy text and picture files, emphasizing the importance of readability when working with multiple files. additionally, it demonstrates working with image files in binary mode, using 'append b to read r and write w', reading and writing specific chunk sizes, and creating an exact copy of the original file, providing a good introduction into file operations.", 'chapters': [{'end': 1089.731, 'start': 828.872, 'title': 'File reading and writing basics', 'summary': 'Covers file reading and writing basics, including using f.seek to change the file position, differentiating write and read modes, and the behavior of seek when writing to files.', 'duration': 260.859, 'highlights': ['The behavior of f.seek to change the position in a file, as demonstrated by using f.seek(0) to set the position back to the beginning of the file, impacting subsequent reads. (e.g. f.seek(0) set the position back to the beginning of the file)', 'Differentiating write and read modes, with an example demonstrating that attempting to write to a file opened in read mode results in an error. (e.g. Attempting to write to a file in read mode results in an error)', "Demonstrating the creation of a new file using the write mode, and the option to either create a new file or overwrite an existing one. (e.g. Using 'w' to create and overwrite existing files, 'a' for appending)", 'Using f.seek when writing to files, where seeking to a specific position only overwrites the necessary content, as illustrated by an example of overwriting specific characters without deleting the rest of the content. (e.g. Demonstrating the partial overwrite behavior of f.seek when writing to files)']}, {'end': 1262.864, 'start': 1090.091, 'title': 'Copying files in python', 'summary': 'Discusses using file objects in python to copy text and picture files, demonstrating the process and emphasizing the importance of readability when working with multiple files.', 'duration': 172.773, 'highlights': ['The process of copying a text file involves opening the original file in read mode and the copy file in write mode, then looping through each line in the original file and writing it to the copy file.', 'Emphasizing the importance of readability, the speaker recommends putting open statements for multiple files on separate lines, nested within each other, to improve understanding and maintain clarity.', "Demonstrates the creation of an exact copy of the original text file using the process described, resulting in the successful creation of the 'test_copy.txt' file.", "Explains the process of copying a large picture file, highlighting the need for a slightly different approach compared to text files and mentioning the specific file 'Bronx.jpg' as an example."]}, {'end': 1465.249, 'start': 1264.025, 'title': 'Working with files in binary mode', 'summary': "Demonstrates working with image files in binary mode, using 'append b to read r and write w', reading and writing specific chunk sizes, and creating an exact copy of the original file, providing a good introduction into file operations.", 'duration': 201.224, 'highlights': ["Creating an exact copy of the original file By using specific chunk sizes and a while loop to write chunks to the copy until there's nothing left to read, an exact copy of the original file is created.", "Working with image files in binary mode Demonstrating the process of working with image files in binary mode, using 'append B to read R and write W' for reading and writing bytes instead of text.", 'Introduction into file operations Providing a good introduction into working with files and some of the useful things that can be done with them, with plans for future tutorials on working with temporary files and in-memory files.']}], 'duration': 636.377, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/Uh2ebFW8OYM/pics/Uh2ebFW8OYM828872.jpg', 'highlights': ['Demonstrating the creation of a new file using the write mode, and the option to either create a new file or overwrite an existing one.', 'Using f.seek when writing to files, where seeking to a specific position only overwrites the necessary content, as illustrated by an example of overwriting specific characters without deleting the rest of the content.', 'The process of copying a text file involves opening the original file in read mode and the copy file in write mode, then looping through each line in the original file and writing it to the copy file.', "Creating an exact copy of the original file By using specific chunk sizes and a while loop to write chunks to the copy until there's nothing left to read, an exact copy of the original file is created.", 'Differentiating write and read modes, with an example demonstrating that attempting to write to a file opened in read mode results in an error.', "Working with image files in binary mode Demonstrating the process of working with image files in binary mode, using 'append B to read R and write W' for reading and writing bytes instead of text."]}], 'highlights': ["Using a context manager with the 'with' keyword is recommended for most use cases to avoid the need to explicitly close files and ensure proper file handling.", 'Context managers automatically handle file closing and cleanup, even in the event of exceptions, promoting it as a best practice.', "Iterating over the lines in a file using 'for line in F' is a memory-efficient method of reading large files.", 'Demonstrating the creation of a new file using the write mode, and the option to either create a new file or overwrite an existing one.']}