Errata for Python for Data Analysis

Found same problem as CJ: 66 In the following line: operating_system = np.where(cframe['a'].str.contains('Windows'), 'Windows', 'Not Windows') np was not defined, so this line gives an error 99 Question: Why don't any of these known errata get confirmed/addressed by the author or staff at O'Reilly?

Note from the Author or Editor:
On page 21 please change the code line In [290]: about halfway down the page from In [290]: import pandas as pd to In [290]: import pandas as pd; import numpy as np This mistake is fairly minor (all things considered) as these code examples are intended to be run in IPython in "pylab" mode (ipython --pylab) which will have imported NumPy and created the np alias. Sorry about that

"float64, float128" should read "float64" only. "float128" already correctly appears on the next line in the table (on page 84).

Note from the Author or Editor:
Correct. Please delete the ", float128" there

1 * cond1 + 2 * cond2 + 3 * -(cond1 | cond2) is not equivalent to the two other code examples offered. In particular, if cond1 and cond2 are both False, the result is 0, not 3.

Note from the Author or Editor:
Oops. Please change that line of code to 1 * (cond1 & -cond2) + 2 * (cond2 & -cond1) + 3 * -(cond1 | cond2)

For pinv description remove the word "square" (this function does not require that the matrices be square)

The description of the copy option for reindex in table 5-5 of the current (as of 8/2/12) preprint version may be wrong. It says that copy is "Do not copy underlying data if new index is equivalent to old index." I believe this is the opposite of copy's behavior, and the words "Do not" should be removed.

Note from the Author or Editor:
Change text to If True, always copy underlying data even if new index is equivalent to old index. Otherwise, do not copy the data when the indexes are equivalent.

The line currently is: frame = DataFrame(np.arange(6).reshape(3, 2)), index=[2, 0, 1]) It should instead be: frame = DataFrame(np.arange(6).reshape(3, 2), index=[2, 0, 1])

Note from the Author or Editor:
Confirmed. please change as described

keep_date_col description is inconsistent with the pandas documention. Should be: If joining columns to parse date, keep the joined columns. Default False

Note from the Author or Editor:
Confirmed. Please change as described

The Output of perf = DataFrame(data) is not correct. As printed: In [928]: perf Out[928]: Empty DataFrame Columns: array([], dtype=int64) Index: array([], dtype=int64) But should be: <class 'pandas.core.frame.DataFrame'> Int64Index: 648 entries, 0 to 647 Data columns: AGENCY_NAME 648 non-null values CATEGORY 648 non-null values DESCRIPTION 648 non-null values FREQUENCY 648 non-null values INDICATOR_NAME 648 non-null values INDICATOR_UNIT 648 non-null values MONTHLY_ACTUAL 648 non-null values MONTHLY_TARGET 648 non-null values PERIOD_MONTH 648 non-null values PERIOD_YEAR 648 non-null values YTD_ACTUAL 648 non-null values YTD_TARGET 648 non-null values dtypes: int64(2), object(10)

Note from the Author or Editor:
Confirmed. Please change the text of Out[928]: to <class 'pandas.core.frame.DataFrame'> Int64Index: 648 entries, 0 to 647 Data columns: AGENCY_NAME 648 non-null values CATEGORY 648 non-null values DESCRIPTION 648 non-null values FREQUENCY 648 non-null values INDICATOR_NAME 648 non-null values INDICATOR_UNIT 648 non-null values MONTHLY_ACTUAL 648 non-null values MONTHLY_TARGET 648 non-null values PERIOD_MONTH 648 non-null values PERIOD_YEAR 648 non-null values YTD_ACTUAL 648 non-null values YTD_TARGET 648 non-null values dtypes: int64(2), object(10)

The section begins: A common way to store multiple time series in databases and CSV is in so-called long or stacked format: In [116]: ldata[:10] However, the variable ldata has not been defined or initialized previously (or later) in the book.

Note from the Author or Editor:
Yeah, I left the code to make that DataFrame out as it was derived in a mungy way from the macrodata used earlier. Editors: please put a note in parentheses after "stacked format" that says "... or stacked format (code to create this DataFrame omitted for brevity):" or something. pretty trivial for the user to type this in

ch07/movies.dat is not there (is in ch02/movielens)

Note from the Author or Editor:
Thanks. please change 'ch07/movies.dat' to 'ch02/movielens/movies.dat' in the code

Table 8-1: the description for 'subplot_kw' is cut off

Note from the Author or Editor:
Please change the description for subplot_kw to Dict of keywords passed to <literal>add_subplot</literal> call used to create each subplot.

scatter_matrix(trans_data, diagonal='kde', color='k', alpha=0.3) should be pd.scatter_matrix(trans_data, diagonal='kde', color='k', alpha=0.3)

Note from the Author or Editor:
Thanks. Please change code as described (add pd. to start of statement)

Should be return totals.order(ascending=False)[:n] (was [-n:])

Note from the Author or Editor:
Correct. Please fix code typo as described (replace [-n:] with [:n])

Out[470] should be 'Period('2007-06', 'M')'

Note from the Author or Editor:
Confirmed, please make change as described There is also a formatting mistake right before "Out [470]:" , please fix that also

In[570]: spx_px is has not been defined in the chapter yet

Note from the Author or Editor:
Please add code line just above In [570]: In [569]: spx_px = close_px_all['SPX'] Make sure there is a blank line between that code line and the next one to keep the styling consistent

arr.reshape((3,4), order=?) should read arr.reshape((4,3), order=?)

Note from the Author or Editor:
Correct, please fix figure text as described. Surprised this one evaded me but it's obvious once you see it =)

Quote from page 364: "See Figure 12-6 for another illustration, this time subtracting a two-dimensional array from a three-dimensional one across axis 0." Figure 12-6 does not show subtraction nor numbers representing numpy data make any sense

Note from the Author or Editor:
The figure and text needs fixing The text: change "subtracting... from ..." to "adding...to..." In the Figure 12-6, change the numbers in the result to be double what they are, so instead of 0, 1, 2, 3, 4, 5, 6, 7, make then in the corresponding order double that, 0, 2, 4, 6, ...

IT IS: loc_mapping = dict((val, idx) for idx, val in enumerate(strings)} SHOULD BE: loc_mapping = dict((val, idx) for idx, val in enumerate(strings)) NOTE: Last character of code line should be ) and not }... probably from wrong copy&paster of previous code line. It's obvious, but I checked this with IPython.

Note from the Author or Editor:
Please fix typo as submitter described (replace curly brace with parenthesis) Thanks!