Data Science

Computational tools

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Which of the following object has a method cov to compute covariance between series?
Series
DataFrame
Panel
None of the mentioned
Explanation:
DataFrame has a method cov to compute pairwise covariances among the series in the DataFrame, also excluding NA/null values.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
Which of the following method produces a data ranking with ties being assigned the mean of the ranks for the group?
rank
dense_rank
partition_rank
none of the mentioned
Explanation:
rank is also a DataFrame method.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
cov and corr supports the optional min_periods keyword.
True
False
Explanation:
Non-numeric columns will be automatically excluded from the correlation calculation.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
Point out the correct statement.
Pandas represents timestamps in microsecond resolution
Pandas is 100% thread safe
For Series and DataFrame objects, var normalizes by N-1 to produce unbiased estimates
All of the mentioned
Explanation:
Pandas represents timestamps in nanosecond resolution.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
Which of the following can potentially change the dtype of a series?
reindex_like
index_like
itime_like
none of the mentioned
Explanation:
reindex_like silently inserts NaNs and the dtype changes accordingly.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
rolling_count function gives the number of non-null observations.
True
False
Explanation:
The binary operators take two Series or DataFrames.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
Which of the following is used to compute the percent change over a given number of periods?
pct_change
percent_change
per_change
none of the mentioned
Explanation:
Series, DataFrame, and Panel all have a method pct_change.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
Which of the following is implemented on DataFrame to compute the correlation between like-labeled Series contained in different DataFrame objects?
corrwith
corwith
corwit
none of the mentioned
Explanation:
A score close to 1 means their tastes are very similar.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
Which of the following specifies the required minimum number of observations for each column pair in order to have a valid result?
min_periods
max_periods
minimum_periods
all of the mentioned
Explanation:
DataFrame.cov also supports an optional min_periods.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
Point out the wrong statement.
lxml is very fast
lxml requires Cython to install correctly
lxml does not make any guarantees about the results of it’s parse
none of the mentioned
Explanation:
There are some versioning issues surrounding the libraries that are used to parse HTML tables in the top-level pandas io function read_html.