Exercise 5.2: Adding data to a data frame¶
[1]:
import pandas as pd
We continue working with the frog tongue data. Recall that the header comments in the data file contained information about the frogs.
[2]:
!head -20 data/frog_tongue_adhesion.csv
# These data are from the paper,
# Kleinteich and Gorb, Sci. Rep., 4, 5225, 2014.
# It was featured in the New York Times.
# http://www.nytimes.com/2014/08/25/science/a-frog-thats-a-living-breathing-pac-man.html
#
# The authors included the data in their supplemental information.
#
# Importantly, the ID refers to the identifites of the frogs they tested.
# I: adult, 63 mm snout-vent-length (SVL) and 63.1 g body weight,
# Ceratophrys cranwelli crossed with Ceratophrys cornuta
# II: adult, 70 mm SVL and 72.7 g body weight,
# Ceratophrys cranwelli crossed with Ceratophrys cornuta
# III: juvenile, 28 mm SVL and 12.7 g body weight, Ceratophrys cranwelli
# IV: juvenile, 31 mm SVL and 12.7 g body weight, Ceratophrys cranwelli
date,ID,trial number,impact force (mN),impact time (ms),impact force / body weight,adhesive force (mN),time frog pulls on target (ms),adhesive force / body weight,adhesive impulse (N-s),total contact area (mm2),contact area without mucus (mm2),contact area with mucus / contact area without mucus,contact pressure (Pa),adhesive strength (Pa)
2013_02_26,I,3,1205,46,1.95,-785,884,1.27,-0.290,387,70,0.82,3117,-2030
2013_02_26,I,4,2527,44,4.08,-983,248,1.59,-0.181,101,94,0.07,24923,-9695
2013_03_01,I,1,1745,34,2.82,-850,211,1.37,-0.157,83,79,0.05,21020,-10239
2013_03_01,I,2,1556,41,2.51,-455,1025,0.74,-0.170,330,158,0.52,4718,-1381
2013_03_01,I,3,493,36,0.80,-974,499,1.57,-0.423,245,216,0.12,2012,-3975
So, each frog has associated with it an age (adult or juvenile), snout-vent-length (SVL), body weight, and species (either cross or cranwelli). For a tidy data frame, we should have a column for each of these values. Your task is to load in the data, and then add these columns to the data frame. For convenience, here is a data frame with data about each frog.
[3]:
df_frog = pd.DataFrame(
data={
"ID": ["I", "II", "III", "IV"],
"age": ["adult", "adult", "juvenile", "juvenile"],
"SVL (mm)": [63, 70, 28, 31],
"weight (g)": [63.1, 72.7, 12.7, 12.7],
"species": ["cross", "cross", "cranwelli", "cranwelli"],
}
)
Note: There are lots of ways to solve this problem. This is a good exercise in searching through the Pandas documentation and other online resources, such as Stack Overflow. Remember, much of your programming efforts are spent searching through documentation and the internet.