python pandas dataframe head() displays nothing

问题

I am new to using pandas and I just don't know what to do with this :

I am using python. I have (properly) installed anaconda. In my file I simply create a DataFrame (first by importing it from read_csv, then recreating it by hand to make sure that was not the problem). When I do print (dataframe) it prints:

        km |  price
0  | 240000 |  3650

[...]

23  | 61789 |  8290

When I do dataframe.info() I get this :

class 'pandas.core.frame.DataFrame'

Int64Index: 24 entries, 0 to 23

Data columns (total 2 columns):

km       24 non-null int64

price    24 non-null int64

dtypes: int64(2)

memory usage: 576.0 bytes

Which is perfect. But any other simple function I try just displays NOTHING. I tried dataframe.head(), dataframe['km'], dataframe[3:6], etc. No errors, just a big bowl of nothing on my terminal.

Edit to add example code:

import pandas as pd 
import numpy as np 
import matplotlib.pyplot as plt 
pd.set_option('max_columns', 50) 
#df=pd.read_csv('data.csv') 
data = {'km': [240000, 139800, 150500, 185530, 176000, 114800, 166800, 89000, 144500, 84000, 82029, 63060, 74000, 97500, 67000, 76025, 48235, 93000, 60949, 65674, 54000, 68500, 22899, 61789], 'price': [3650, 3800, 4400, 4450, 5250, 5350, 5800, 5990, 5999, 6200, 6390, 6390, 6600, 6800, 6800, 6900, 6900, 6990, 7490, 7555, 7990, 7990, 7990, 8290]} 
df = pd.DataFrame(data, columns=['km', 'price']) 
print (df) 
df.info() 
df[2:5] 
df["km"] 

回答1:

You have to use:

print(dataframe.head())
print(dataframe['km'])
print(dataframe[3:6])

Without the print statement python is just selecting the data but not doing anything with it.

回答2:

You may expect this would show some row after seeing how other does. But this only appear only in terminal environment. Just like the above answer, you need an print() to show row while you are using ide

来源：https://stackoverflow.com/questions/33483707/python-pandas-dataframe-head-displays-nothing