Python 3 Count number of rows in a CSV

Question

Im having trouble getting the row count in a python 3 environment after migrating from 2.7. After several attempts the number of rows returned gives one. How do I get around a DeprecationWarning: 'U' mode is deprecated in python 3 ?

             input_file = open("test.csv","rU")
             reader_file = csv.reader(input_file)
             value = len(list(reader_file))

In the case of using python 3 Ive tried the following approach but Im still stuck with a 1.

             input_file = open("test.csv","rb")
             reader_file = csv.reader(input_file)
             value = len(list(reader_file))

Possible duplicate of Count how many lines are in a CSV Python? — Masoud
– Masoud, Commented Jun 4, 2019 at 1:34
>>> len(list(csv.reader(open(r'new.csv')))) works for me. Your file only has one line. — wwii
– wwii, Commented Jun 4, 2019 at 2:41

Vim · Accepted Answer · 2019-06-04 03:03:19Z

16

If you are using pandas you can easily do that, without much coding stuff.

import pandas as pd

df = pd.read_csv('filename.csv')

## Fastest would be using length of index

print("Number of rows ", len(df.index))

## If you want the column and row count then

row_count, column_count = df.shape

print("Number of rows ", row_count)
print("Number of columns ", column_count)

answered Jun 4, 2019 at 3:03

Vim

5885 silver badges16 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

BKCapri Over a year ago

Much better though im still one row short

CustardBun Over a year ago

If you do read_csv and you're skipping bad lines, is there a way to get both the # of lines in the original CSV vs in the dataframe post-read?

DYZ · Accepted Answer · 2019-06-04 01:27:43Z

0

input_file = open("test.csv","rb") #rb is a read-in-binary format and 
#you can't count the number of row from binary format file

with open("text.csv",'r') as f:
file = f.readlines()
print(len(file))

# Data in my text file
# a
# b
# c
# d
# e

#The output of above code is 
#5 means number of rows is 5

edited Jun 4, 2019 at 1:27

DYZ

57.3k10 gold badges73 silver badges101 bronze badges

answered Jun 4, 2019 at 0:46

Saad Fayyaz

114 bronze badges

Collectives™ on Stack Overflow

Python 3 Count number of rows in a CSV

2 Answers 2

2 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related