|
| 1 | +# Basic File Handling |
| 2 | + |
| 3 | + |
| 4 | +## Writing |
| 5 | + |
| 6 | +Open file in current directory to overwrite file contents. Creates file if it doesn't exist. |
| 7 | +``` |
| 8 | +file = open("file.txt", "w") |
| 9 | +file.write("hello earth!") |
| 10 | +``` |
| 11 | +File contents: |
| 12 | +``` |
| 13 | +hello earth! |
| 14 | +``` |
| 15 | +## Reading |
| 16 | + |
| 17 | +Open file for read only. Read entire contents of file. |
| 18 | +``` |
| 19 | +file = open("file.txt", "r") |
| 20 | +file_contents = file.read() |
| 21 | +``` |
| 22 | +Reads: |
| 23 | +``` |
| 24 | +hello earth! |
| 25 | +``` |
| 26 | + |
| 27 | +## Appending |
| 28 | + |
| 29 | +Open file for appending. This means the existing file content is kept. |
| 30 | +``` |
| 31 | +file = open("file.txt", "a") |
| 32 | +file.write("\nhello universe!") # note:"\n" writes a newline |
| 33 | +``` |
| 34 | +File contents: |
| 35 | +``` |
| 36 | +hello earth! |
| 37 | +hello universe! |
| 38 | +``` |
| 39 | +## Read file line by line |
| 40 | + |
| 41 | +Make a list holding each line in the file |
| 42 | +``` |
| 43 | +file = open("file.txt", "r") |
| 44 | +lines_in_file = file.readlines() |
| 45 | + |
| 46 | +for each_line in lines_in_file: |
| 47 | + print(each_line) |
| 48 | +``` |
| 49 | +prints: |
| 50 | +``` |
| 51 | +hello earth! |
| 52 | +hello universe! |
| 53 | +``` |
| 54 | + |
| 55 | +## Check if file exists |
| 56 | + |
| 57 | +``` |
| 58 | +from pathlib import Path |
| 59 | + |
| 60 | +file_to_find = Path("file.txt") |
| 61 | + |
| 62 | +if file_to_find.exists(): |
| 63 | + print("file exists") |
| 64 | +else: |
| 65 | + print("file not found") |
| 66 | +``` |
| 67 | + |
| 68 | +## Delete file |
| 69 | + |
| 70 | +``` |
| 71 | +from pathlib import Path |
| 72 | + |
| 73 | +file_to_delete = Path("file.txt") |
| 74 | +file_to_delete.unlink() |
| 75 | +``` |
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