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?](https://stackoverflow.com/questions/16108526/count-how-many-lines-are-in-a-csv-python) — Masoud, Jun 04 '19 at 01:34
`>>> len(list(csv.reader(open(r'new.csv'))))` works for me. Your file only has one line. — wwii, Jun 04 '19 at 02:41

score 16 · Accepted Answer · answered Jun 04 '19 at 03:03

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 04 '19 at 03:03

Vim

578
5
16

Much better though im still one row short – BKCapri Jun 05 '19 at 00:49
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? – CustardBun Oct 15 '20 at 23:41

score 0 · Answer 2 · edited Jun 04 '19 at 01:27

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 04 '19 at 01:27

DYZ

55,249
10
64
93

answered Jun 04 '19 at 00:46

Saad Fayyaz

11
4

Python 3 Count number of rows in a CSV

2 Answers2

Linked