how to count number of lines in a file in python code example

Example 1: python how to count the lines in a file

# Basic syntax:
count = len(open('/path/to/the/file.ext').readlines())

Example 2: Write a Python program to count the number of lines in a text file.

def countlines(fname,mode='r+'):
	count=0
	with open(fname) as f:
		for _ in f:
			count += 1
	print('total number of lines in file : ',count)

countlines('file1.txt')

##########################

with open('file1.txt') as f:
	print(sum(1 for _ in f))
##########################
with open('file1.txt') as f:
	for lno , line in enumerate(f,1):
		pass
	print('total lines:',lno)

###########################
'''You can use len(f.readlines()),
 but this will create an additional list in memory,
  which won't even work on huge files that don't fit in memory.

'''