In [1]:
import pandas as pd
import numpy as np
import matplotlib as plt
import matplotlib.pyplot as plt'ggplot')
In [2]:
cols = ['Rank', 'Country', 'UN_Continental_region', 'UN_Statistical_region', 
        'Population', 'Population2015', 'percent_change']
In [3]:
##  There is problem your numeric data contains bad data (strings) or numeric data are converted to str.
##  So first try convert to float or int by astype:
#pop_list['Population'] = pop_list['Population'].astype(float)
##  But if it failed need to_numeric with parameter errors='coerce':
#pop_list['Population'] = pd.to_numeric(pop_list['Population'], errors='coerce')
In [4]:
pop_list = pd.read_table('country.dat', names=cols)
In [5]:
Rank                      int64
Country                  object
UN_Continental_region    object
UN_Statistical_region    object
Population                int64
Population2015            int64
percent_change           object
dtype: object
In [6]:
/Users/npr1/astroconda/lib/python3.5/site-packages/ipykernel/ RuntimeWarning: Tried to set a label via parameter 'x' in func 'hist' but couldn't find such an argument. 
(This is a programming error, please report to the matplotlib list!)
  from ipykernel import kernelapp as app
TypeError                                 Traceback (most recent call last)
<ipython-input-6-b77294b82800> in <module>()
      1 #pop_list['Population'].plot().hist('Population')
----> 2 pop_list['Population'].plot().hist(alpha=0.5)
      3 #pop_list.plot.hist(alpha=0.5)
      4 #pop_list.plot.hist('Population')

/Users/npr1/astroconda/lib/python3.5/site-packages/matplotlib/ in inner(ax, *args, **kwargs)
   1890                     warnings.warn(msg % (label_namer, func.__name__),
   1891                                   RuntimeWarning, stacklevel=2)
-> 1892             return func(ax, *args, **kwargs)
   1893         pre_doc = inner.__doc__
   1894         if pre_doc is None:

TypeError: hist() missing 1 required positional argument: 'x'
In [7]: