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Change one value based on another value in pandas
...ere.
Assuming you can load your data directly into pandas with pandas.read_csv then the following code might be helpful for you.
import pandas
df = pandas.read_csv("test.csv")
df.loc[df.ID == 103, 'FirstName'] = "Matt"
df.loc[df.ID == 103, 'LastName'] = "Jones"
As mentioned in the comments, you ...
PostgreSQL query to list all table names?
Is there any query available to list all tables in my Postgres DB.
7 Answers
7
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Reading InputStream as UTF-8
...ug that the OutputStreamWriter constructors have: only one of the four actually condescends to tell you when something goes wrong. You again have to use the fancy CharsetDecoder dec argument there, too. The only safe and sane thing to do is to consider all other constructors deprecated, because they...
Pandas every nth row
...simpler solution to the accepted answer that involves directly invoking df.__getitem__.
df = pd.DataFrame('x', index=range(5), columns=list('abc'))
df
a b c
0 x x x
1 x x x
2 x x x
3 x x x
4 x x x
For example, to get every 2 rows, you can do
df[::2]
a b c
0 x x x
...
Remove all occurrences of char from string
...argument is regular expression, sometimes it won't work as expected, especially if this string comes from user input.
– vbezhenar
Jul 4 '12 at 8:50
9
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mysql :: insert into table, data from another table?
...
INSERT INTO action_2_members (campaign_id, mobile, vote, vote_date)
SELECT campaign_id, from_number, received_msg, date_received
FROM `received_txts`
WHERE `campaign_id` = '8'
...
C# Interfaces. Implicit implementation versus Explicit implementation
...ImplementedException();
}
The difference is that implicit implementation allows you to access the interface through the class you created by casting the interface as that class and as the interface itself. Explicit implementation allows you to access the interface only by casting it as the interfa...
javascript scroll event for iPhone/iPad?
... onscroll only after you've stopped scrolling.
The usual way of installing the handler works e.g.
window.addEventListener('scroll', function() { alert("Scrolled"); });
// or
$(window).scroll(function() { alert("Scrolled"); });
// or
window.onscroll = function() { alert("Scrolled"); };
// etc...
Determine Whether Two Date Ranges Overlap
...
Proof:
Let ConditionA Mean that DateRange A Completely After DateRange B
_ |---- DateRange A ------|
|---Date Range B -----| _
(True if StartA > EndB)
Let ConditionB Mean that DateRange A is Completely Before DateRange B
|---- DateRange A ...
John Carmack's Unusual Fast Inverse Square Root (Quake III)
...s derived is something of a mystery.
To quote Gary Tarolli:
Which actually is doing a floating
point computation in integer - it took
a long time to figure out how and why
this works, and I can't remember the
details anymore.
A slightly better constant, developed by an expert mathemat...