I am trying to sort the following Pandas DataFrame in Python:
import numpy as np
import pandas as pd
heading_cols = [
"Video Title",
"Up Ratings",
"Down Ratings",
"Views",
"User Name",
"Subscribers",
]
column_1 = [
"Adelaide",
"Brisbane",
"Darwin",
"Hobart",
"Sydney",
"Melbourne",
"Perth",
]
column_2 = [1295, 5905, 112, 1357, 2058, 1566, 5386]
column_3 = [1158259, 1857594, 120900, 205556, 4336374, 3806092, 1554769]
column_4 = [600.5, 1146.4, 1714.7, 619.5, 1214.8, 646.9, 869.4]
column_5 = ["Bob","Tom","Dave","Sally","Rick","Mary","Roberta"]
column_6 = [25000,30000,15000,15005,20000,31111,11000]
#Generate data:
xdata_arr = np.array([column_1,column_2,column_3,column_4,column_5,column_6]).T
# Generate the DataFrame:
df = pd.DataFrame(xdata_arr, columns=heading_cols)
print(df)
The next 2 lines of code are causing problems:
# Print DataFrame and basic stats:
print(df["Up Ratings"].describe())
print(df.sort('Views', ascending=False))
Problems:
The problem is that dtypes() is returning "object" for all the columns. This is wrong. some should be integers, but I can't figure out how to change only the numeric ones. I have tried:
df.convert_objects(convert_numeric=True)
but this is not working. So, then I went to the NumPy array and tried to change the dtypes there:
dt = np.dtype(
[
(heading_cols[0], np.str_),
(heading_cols[1], np.int16),
(heading_cols[2], np.int16),
(heading_cols[3], np.int16),
(heading_cols[4], np.str_),
(heading_cols[5], np.int16),
]
)
but this does not work either.
Is there a way to manually change the dtype to numeric?
Like most methods in pandas, convert_objects returns a NEW object.
In [20]: df.convert_objects(convert_numeric=True)
Out[20]:
Video Title Up Ratings Down Ratings Views User Name Subscribers
0 Adelaide 1295 1158259 600.5 Bob 25000
1 Brisbane 5905 1857594 1146.4 Tom 30000
2 Darwin 112 120900 1714.7 Dave 15000
3 Hobart 1357 205556 619.5 Sally 15005
4 Sydney 2058 4336374 1214.8 Rick 20000
5 Melbourne 1566 3806092 646.9 Mary 31111
6 Perth 5386 1554769 869.4 Roberta 11000
In [21]: df.convert_objects(convert_numeric=True).dtypes
Out[21]:
Video Title object
Up Ratings int64
Down Ratings int64
Views float64
User Name object
Subscribers int64
dtype: object