Search Substring in File
Search for a substring in a text file and report matching line numbers.
BeginnerTopic: File Handling Programs
Python Search Substring in File Program
This program helps you to learn the fundamental structure and syntax of Python programming.
# Program to search for a substring in a file
filename = input("Enter filename: ")
term = input("Enter search term: ")
try:
with open(filename, "r", encoding="utf-8") as f:
for line_no, line in enumerate(f, start=1):
if term in line:
print(f"Found on line {line_no}: {line.strip()}")
except FileNotFoundError:
print("File not found.")Output
Enter filename: notes.txt Enter search term: Python Found on line 3: Learning Python basics
Understanding Search Substring in File
Reads file line by line, checking membership of the substring and printing matching lines.
Note: To write and run Python programs, you need to set up the local environment on your computer. Refer to the complete article Setting up Python Development Environment. If you do not want to set up the local environment on your computer, you can also use online IDE to write and run your Python programs.