Let say this in the input CSV file.
I would like to go over the Babys column and change it to increasing number by 1.
what i did is to count how many row there are in the file, and run a for loop on all of them. But i cant figure out how to change the values
v = open(input.csv)
r=csv.reader(v)
numline = len(v.readlines())
print (numline)
for row in r:
if row["Baby"] == "Baby":
for i in range (1, numline):
print("test")
It can be done very easily when using pandas module
import pandas as pd
# read/parse CSV into pandas data frame
df = pd.read_csv('input.csv', delim_whitespace=True)
Output:
In [33]: df
Out[33]:
Name Age Babys
0 Avi 25 1
1 Dav 24 1
2 Ela 30 1
3 Ron 40 1
4 Shi 33 1
5 Leb 22 1
6 Moe 11 1
conditionally increase Babys column by 1
df.loc[(df.Name.isin(['Avi','Dav','Ron'])) & (df.Age < 33), 'Babys'] += 1
Output:
In [35]: df
Out[35]:
Name Age Babys
0 Avi 25 2
1 Dav 24 2
2 Ela 30 1
3 Ron 40 1
4 Shi 33 1
5 Leb 22 1
6 Moe 11 1
increase Babys column by 1 for all rows (unconditionally)
df.Babys += 1
Output:
In [43]: df
Out[43]:
Name Age Babys
0 Avi 25 3
1 Dav 24 3
2 Ela 30 2
3 Ron 40 2
4 Shi 33 2
5 Leb 22 2
6 Moe 11 2
Finally save changed DF back to CSV file:
df.to_csv('d:/temp/out.csv', index=False, sep=',')
out.csv:
Name,Age,Babys
Avi,25,3
Dav,24,3
Ela,30,2
Ron,40,2
Shi,33,2
Leb,22,2
Moe,11,2
You can use python pandas to increase the column number by n:
import pandas
data_df = pandas.read_csv('input.csv')
data_df = data_df['age'].apply(lambda x: x+n)
print data_df
for adding 1 replace n by 1.
