Python Pandas Find Starting/ending Row And Rounding Numbers

import pandas as pd import numpy as np import urllib url = 'http://cawcr.gov.au/staff/mwheeler/maproom/RMM/RMM1RMM2.74toRealtime.txt' urllib.urlretrieve(url,'datafile.txt') df =

Solution 1:

To quickly answer your last question, use:

import numpy as np
np.round(ec, 0)

For your first (series of) question(s), you don't give us any data to play with and your questions isn't very clear. Either way, you can always get the the first and last rows of any dataframe with df.iloc[0] and df.iloc[-1], respectively.

Edits:

If you simply need to know how many rows you have, use df.shape. Here's a toy example:

import pandas

df = pandas.DataFrame([
    (1977, 1, 1),
    (1978, 1, 2),
    (1979, 1, 3),
    (1980, 1, 4),
    (1977, 2, 1),
    (1978, 2, 2),
    (1979, 2, 3),
    (1980, 2, 4),
    (1977, 3, 1),
    (1978, 3, 2),
    (1979, 3, 3),
    (1980, 3, 4),
], columns=['year', 'a', 'b'])
print(df.to_string())

Which prints:

    year  a  b
0   1977  1  1
1   1978  1  2
2   1979  1  3
3   1980  1  4
4   1977  2  1
5   1978  2  2
6   1979  2  3
7   1980  2  4
8   1977  3  1
9   1978  3  2
10  1979  3  3
11  1980  3  4

And then:

df = df[df.year > 1978]
df = df[df.a < 3]
print(df.to_string())

which gives:

   year  a  b
2  1979  1  3
3  1980  1  4
6  1979  2  3
7  1980  2  4

Try this our yourself after executing everything above:

print(df.shape)

for row in range(df.shape[0]-1):
    print(df.iloc[row])

For rounding:

df = pandas.DataFrame(np.random.normal(size=(4,4)))
rounded = np.round(df,1)
print(rounded.to_string())
     0    1    2    3
0 -1.2  1.9  0.7 -0.8
1 -0.5  0.9  1.6 -0.3
2  0.4 -0.2 -1.6 -0.2
3 -1.7  1.1  0.1 -0.6