Read Entire File with read()
read() returns the whole file content as a single string. Pass an integer to read only that many characters.
with open("example.txt", "w") as f:
f.write("Line one\nLine two\nLine three")
with open("example.txt", "r") as f:
data = f.read()
print(data)Read Line by Line with readline()
readline() reads one line at a time. Each call moves the file cursor to the next line. Returns an empty string at the end.
with open("example.txt", "r") as f:
line1 = f.readline()
line2 = f.readline()
print(repr(line1), repr(line2))Loop Through a File
A file object is iterable. Looping over it yields one line per iteration — efficient even for huge files.
with open("example.txt", "r") as f:
for line in f:
print(line.strip())