How to replace values in column for every rows with same values in Pandas

Question

I have a DataFrame that looks like this:

In [10]: import pandas as pd
In [11]: df = pd.read_table("http://dpaste.com/2M75260.txt",sep=",")
In [12]: df.head(n=3L)
Out[12]:
             ID    Genes  Foldchange
0    1415670_at     Copg       0.989
1    1415673_at     Psph       1.004
2  1415674_a_at  Trappc4       1.000

In actuality there are around 40K rows. What I want to do is to change the all the values in Foldchange with same value 2.

So that it will looks like:

ID            Genes  Foldchange
1415670_at     Copg       2.000
1415673_at     Psph       2.000
1415674_a_at  Trappc4     2.000
.... etc...

How can I do that conveniently in Pandas?

Stefan · Accepted Answer · 2016-01-18 02:04:59Z

5

You should be able to simply:

df.loc[:, 'Foldchange'] = 2

answered Jan 18, 2016 at 2:04

Stefan

43.1k13 gold badges80 silver badges84 bronze badges

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

Comments

NinjaGaiden · Accepted Answer · 2016-01-18 03:49:09Z

4

Similar to Stefan, you can also do

df['Foldchange']=2.0

answered Jan 18, 2016 at 3:49

NinjaGaiden

3,1467 gold badges34 silver badges50 bronze badges

Comments

Community · Accepted Answer · 2017-05-23 11:52:01Z

-2

I don't know pandas, but a quick search: Python pandas equivalent for replace

Since read_table returns a dataframe, you should be able to do a list comprehension or map() with the result() method.

edited May 23, 2017 at 11:52

CommunityBot

11 silver badge

answered Jan 18, 2016 at 2:09

A Small Shell Script

6205 silver badges7 bronze badges

2 Comments

Software Prophets Over a year ago

Since the question is, "How can I do that conveniently in Pandas?" and your response starts with, "I don't know pandas" - How about electing not to post. At this point, removing this response might be helpful since it doesn't add value to the conversation.

A Small Shell Script Over a year ago

The link provided is to another SO which answered the question as initially asked with several examples and two strong answers. I do not need Pandas experience to recognize a duplicate/similar question which could answer the posters question and avoid people re-explaining something. If anything, the constructive criticism you point out is that admitting no experience with the product does not inform the usefulness of the link and should have been omitted.

Collectives™ on Stack Overflow

How to replace values in column for every rows with same values in Pandas

3 Answers 3

Comments

Comments

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related