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Commit b75c98f

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simplify according to feedback
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‎lectures/python_essentials.md‎

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@@ -326,31 +326,40 @@ out
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print(out)
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```
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We can also use `with` statement to contain operations on the file within a block for clarity and cleanness.
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We can also use a `with` statement (also known as a [context manager](https://realpython.com/python-with-statement/#the-with-statement-approach)) which enables you to group operations on the file within a block which improves the clarity of your code.
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```{code-cell} python3
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with open('newfile.txt', 'a+') as file:
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# Adding a line at the end
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file.write('\nAdding a new line')
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# Move the pointer back to the top
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file.seek(0)
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# Read the file line-by-line from the first line
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```{code-cell} python3
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with open("newfile.txt", "r") as f:
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file = f.readlines()
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with open("output.txt", "w") as fo:
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for i, line in enumerate(file):
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print(f'Line {i}: {line}')
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fo.write(f'Line {i}: {line} \n')
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```
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Note that we used `a+` mode (standing for append+ mode) to allow appending new content at the end of the file and enable reading at the same time.
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```{code-cell} python3
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fo = open('output.txt', 'r')
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out = fo.read()
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print(out)
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```
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There are [many modes](https://www.geeksforgeeks.org/reading-writing-text-files-python/) you could set when opening the file.
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We can write the example above under the same context to reduce redundancy
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When experimenting with different modes, it is important to check where the pointer is set.
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```{code-cell} python3
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with open("newfile.txt", "r") as f, open("output2.txt", "w") as fo:
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for i, line in enumerate(f):
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fo.write(f'Line {i}: {line} \n')
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```
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The pointer is set to the end of the file in `a+` mode.
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```{code-cell} python3
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fo = open('output2.txt', 'r')
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out = fo.read()
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print(out)
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```
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Here we set `file.seek(0)` to move the pointer back to the first line (line 0) of the file to print the whole file.
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```{note}
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Note that we only used `r` and `w` mode. There are [more modes](https://www.geeksforgeeks.org/reading-writing-text-files-python/) you could experiment with.
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```
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