File Handling

Understanding how to read from and write to files, and handling file paths.

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1

How do you read the contents of a file in Python?

with open('example.txt', 'r') as file:
    content = file.read()
    print(content)

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2

How do you write text to a file in Python?

with open('example.txt', 'w') as file:
    file.write('Hello, World!')

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3

How do you append text to an existing file?

with open('example.txt', 'a') as file:
    file.write('\nAppended text.')

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4

How can you read a file line by line?

with open('example.txt', 'r') as file:
    for line in file:
        print(line.strip())

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5

How do you read a specific number of bytes from a file?

with open('example.txt', 'r') as file:
    content = file.read(5)  # Reads first 5 bytes
    print(content)

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6

How can you check if a file exists before reading it?

import os

if os.path.exists('example.txt'):
    with open('example.txt', 'r') as file:
        content = file.read()
        print(content)
else:
    print('File does not exist.')

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7

How do you handle exceptions when working with files?

try:
    with open('example.txt', 'r') as file:
        content = file.read()
except FileNotFoundError:
    print('File not found.')
except IOError:
    print('Error reading file.')

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8

How do you get the current working directory?

import os

print(os.getcwd())

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9

How can you change the current working directory?

import os

os.chdir('/path/to/directory')
print(os.getcwd())

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10

How do you write a list of strings to a file, each on a new line?

lines = ['First line', 'Second line', 'Third line']

with open('example.txt', 'w') as file:
    file.write('\n'.join(lines))

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11

How can you read a file into a list of lines?

with open('example.txt', 'r') as file:
    lines = file.readlines()
    print(lines)

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12

How do you delete a file?

import os

os.remove('example.txt')

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13

How do you rename a file?

import os

os.rename('oldname.txt', 'newname.txt')

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14

How do you copy a file to a new location?

import shutil

shutil.copy('source.txt', 'destination.txt')

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15

How can you move a file to a new location?

import shutil

shutil.move('source.txt', 'destination_folder/destination.txt')

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16

How do you create a new directory?

import os

os.makedirs('new_directory', exist_ok=True)

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17

How can you list all files in a directory?

import os

files = os.listdir('directory_path')
print(files)

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18

How do you read binary data from a file?

with open('example.bin', 'rb') as file:
    binary_data = file.read()
    print(binary_data)

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19

How do you write binary data to a file?

binary_data = b'\x00\x01\x02'

with open('example.bin', 'wb') as file:
    file.write(binary_data)

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20

How can you use os.path.join to handle file paths?

import os

file_path = os.path.join('folder', 'file.txt')
with open(file_path, 'w') as file:
    file.write('Hello, World!')

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21

How do you get the size of a file?

import os

file_size = os.path.getsize('example.txt')
print(f'File size: {file_size} bytes')

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22

How can you use pathlib to handle file paths?

from pathlib import Path

file_path = Path('folder') / 'file.txt'
with file_path.open('w') as file:
    file.write('Hello, World!')

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23

How do you check if a path is a file or directory using pathlib?

from pathlib import Path

path = Path('example.txt')
if path.is_file():
    print('Path is a file.')
elif path.is_dir():
    print('Path is a directory.')

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24

How can you read a CSV file into a list of dictionaries?

import csv

with open('example.csv', 'r') as file:
    reader = csv.DictReader(file)
    data = [row for row in reader]
    print(data)

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25

How do you write a list of dictionaries to a CSV file?

import csv

data = [
    {'name': 'Alice', 'age': 25},
    {'name': 'Bob', 'age': 30}
]

with open('example.csv', 'w', newline='') as file:
    writer = csv.DictWriter(file, fieldnames=['name', 'age'])
    writer.writeheader()
    writer.writerows(data)

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