Python working a bit differently to JavaScript for example, the value you are concatenating needs to be same type, both int or str… So for example the code below throw an error: like this: To solve the issue, just add str to your number or value like: And the result as:
j is an empty list, but you’re attempting to write to element [0] in the first iteration, which doesn’t exist yet. Try the following instead, to add a new element to the end of the list: Of course, you’d never do this in practice if all you wanted to do was to copy an existing list. You’d just … Read more
Edit 2017 As indicated in the comments and by @Alexander, currently the best method to add the values of a Series as a new column of a DataFrame could be using assign: Edit 2015Some reported getting the SettingWithCopyWarning with this code.However, the code still runs perfectly with the current pandas version 0.16.1. The SettingWithCopyWarning aims to inform of a possibly … Read more
The easiest and purest method without relying on C headers is PyYaml (documentation), which can be installed via pip install pyyaml: And that’s it. A plain yaml.load() function also exists, but yaml.safe_load() should always be preferred unless you explicitly need the arbitrary object serialization/deserialization provided in order to avoid introducing the possibility for arbitrary code execution. Note the PyYaml project … Read more
If you want to format a datetime object in a specific format that is different from the standard format, it’s best to explicitly specify that format:
If you don’t need atomicity you can use os module: UPDATE: As Cory Klein mentioned, on Mac OS for using os.mknod() you need a root permissions, so if you are Mac OS user, you may use open() instead of os.mknod()
As pointed out by @amit-gupta in the question above, sklearn.cross_validation has been deprecated. The function train_test_split can now be found here: Simply replace the import statement from the question to the one above.
With new_list = my_list, you don’t actually have two lists. The assignment just copies the reference to the list, not the actual list, so both new_list and my_list refer to the same list after the assignment. To actually copy the list, you have various possibilities: You can use the builtin list.copy() method (available since Python 3.3):new_list = old_list.copy() You can slice it:new_list … Read more
figure tells you the call signature: figure(figsize=(1,1)) would create an inch-by-inch image, which would be 80-by-80 pixels unless you also give a different dpi argument.
Yes, it is a hash mapping or hash table. You can read a description of python’s dict implementation, as written by Tim Peters, here. That’s why you can’t use something ‘not hashable’ as a dict key, like a list: You can read more about hash tables or check how it has been implemented in python and why it is implemented that … Read more