The short version is: The efficient way to use readlines() is to not use it. Ever. I read some doc notes on readlines(), where people has claimed that this readlines() reads whole file content into memory and hence generally consumes more memory compared to readline() or read(). The documentation for readlines() explicitly guarantees that it … Read more
Python 3.x does have reduce, you just have to do a from functools import reduce. It also has “dict comprehensions”, which have exactly the syntax in your example. Python 2.7 and 3.x also have a Counter class which does exactly what you want: from collections import Counter cnt = Counter(“abracadabra”) In Python 2.6 or earlier, … Read more
The biggest reason to keep the try/except/finally blocks in the code itself is that error recovery is usually an integral part of the function. For example, if we had our own int() function: def MyInt(text): return int(text) What should we do if text cannot be converted? Return 0? Return None? If you have many simple … Read more
The best direct way to fix this is to remove the global declaration from underneath if __name__ == ‘__main__’:. You don’t need it there. Unlike some other languages, an if statement doesn’t introduce a new scope in Python – any variables you assign in that block are global, just as they would be without the … Read more
You need to commit the data. Each SQL command is in a transaction and the transaction must be committed to write the transaction to the SQL Server so that it can be read by other SQL commands. Under MS SQL Server Management Studio the default is to allow auto-commit which means each SQL command immediately … Read more
A sidenote for someone just wanting a simple dictionary and never needing multiple values with the same key, try: dict(urlparse.parse_qsl(‘foo=bar&baz=qux’)) This will give you a nice {‘foo’: ‘bar’, ‘baz’: ‘qux’}. Please note that if there are multiple values for the same key, you’ll only get the last one.
ast.visit — unless you override it in a subclass, of course — when called to visit an ast.Node of class foo, calls self.visit_foo if that method exists, otherwise self.generic_visit. The latter, again in its implementation in class ast itself, just calls self.visit on every child node (and performs no other action). So, consider, for example: … Read more
For python2.x use following command: python -m pip install cffi for python3.x python3 -m pip install cffi
Whatever your XML string is, you can write it to the file of your choice by opening a file for writing and writing the string to the file. from xml.dom import minidom xmlstr = minidom.parseString(ET.tostring(root)).toprettyxml(indent=” “) with open(“New_Database.xml”, “w”) as f: f.write(xmlstr) There is one possible complication, especially in Python 2, which is both less … Read more
import os random_string = os.urandom(string_length) and if you need url safe string : import os random_string = os.urandom(string_length).hex() (note random_string length is greatest than string_length in that case)