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Create list of single item repeated N times
...ts . To create unique empty sub-lists, use for-comprehension: [[] for i in range(0,n)]
– Josiah Yoder
Aug 15 '17 at 17:01
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How can I rename a database column in a Ruby on Rails migration?
...nd doing one row at a time. The migration would execute much faster with raw sql statements to update correctly named columns. For example, in the first db migration script, after adding the duplicate column names, execute "Update table_name set correct_name_column_one = old_name_column_one"
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MySql: Tinyint (2) vs tinyint(1) - what is the difference?
...isplay width.
It's important to note that it does not affect the accepted range of values for that particular type, i.e. TINYINT(1) still accepts [-128 .. 127].
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Automatically create an Enum based on values in a database lookup table?
...t to the name of an enumeration. The enumeration restricts the valid value range for a different property of the same object. In my case I'm loading metadata, including the valid value range from a database; and no, the vendor code does not support passing a collection of any type to the property. T...
Is BCrypt a good hashing algorithm to use in C#? Where can I find it? [closed]
...d all the bcrypt hashed passwords to the new hashes? Wouldnt they need the raw passwords to hash it using the new algorithm?
– Dharmendar Kumar 'DK'
Jan 6 '14 at 22:44
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Are tuples more efficient than lists in Python?
... advantage:
>>> import sys
>>> sys.getsizeof(tuple(iter(range(10))))
128
>>> sys.getsizeof(list(iter(range(10))))
200
Here is the comment from Objects/listobject.c that explains what lists are doing:
/* This over-allocates proportional to the list size, making room
* ...
How to create a trie in Python
... may take up to 50x-100x less memory than
in a standard Python dict; the raw lookup speed is comparable; trie
also provides fast advanced methods like prefix search.
Based on marisa-trie C++ library.
Here's a blog post from a company using marisa trie successfully:
https://www.repustate.c...
Extract a substring from a string in Ruby using a regular expression
...an array of the captures
matchdata.captures # ["ants","pants"]
# Or use raw indices
matchdata[0] # whole regex match: "<ants> <pants>"
matchdata[1] # first capture: "ants"
matchdata[2] # second capture: "pants"
...
How to get value from form field in django framework?
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This answer best summarises all the options - accessing raw POST data, unvalidated form fields and finally validated form fields.
– Serge Merzliakov
Jun 30 '17 at 4:12
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How to think in data stores instead of databases?
...ey, and fetch operations are limited to fetching single keys or contiguous ranges of keys. More sophisticated queries are made possible with indexes, which are basically just tables of their own, allowing you to implement more complex queries as scans on contiguous ranges.
Once you've absorbed that,...