📖 Reading Files Effectively — Different Approaches

Master different techniques for reading files depending on your needs.

🎯 Read Entire File

Use `read()` to load the entire file into memory as a string.

file = open("document.txt", "r")
content = file.read()  # Returns entire file as one string
print(content)
file.close()

# File content:
# Hello, World!
# This is a test file.
# It has multiple lines.
#
# Output: Hello, World!\nThis is a test file.\nIt has multiple lines.

💡 Read Line by Line

Use `readline()` for one line at a time, or iterate directly.

file = open("data.txt", "r")

# Read one line at a time
line1 = file.readline()  # "Line 1\n"
line2 = file.readline()  # "Line 2\n"

file.close()

# Better: iterate through lines
file = open("data.txt", "r")
for line in file:
    print(line.strip())  # Remove newline

file.close()

🎨 Read All Lines as List

Use `readlines()` to get all lines as a list.

file = open("config.txt", "r")
lines = file.readlines()  # Returns list of strings

# Each element includes the newline character
for line in lines:
    print(repr(line))  # Shows '\n' characters

file.close()

📊 Common Reading Patterns

🔑 Key Takeaways

• ✅ `read()` for entire file as string

• ✅ `readline()` for one line

• ✅ `for line in file:` for iteration

• ✅ `readlines()` returns list of lines

• ✅ Strip newlines with `.strip()`

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