To delete a key regardless of whether it is in the dictionary, use the two-argument form of dict.pop(): my_dict.pop(‘key’, None) This will return my_dict[key] if key exists in the dictionary, and None otherwise. If the second parameter is not specified (i.e. my_dict.pop(‘key’)) and key does not exist, a KeyError is raised. To delete a key … Read more
>>> a = “545.2222” >>> float(a) 545.22220000000004 >>> int(float(a)) 545
RENAME SPECIFIC COLUMNS Use the df.rename() function and refer the columns to be renamed. Not all the columns have to be renamed: df = df.rename(columns={‘oldName1’: ‘newName1’, ‘oldName2’: ‘newName2’}) # Or rename the existing DataFrame (rather than creating a copy) df.rename(columns={‘oldName1’: ‘newName1’, ‘oldName2’: ‘newName2’}, inplace=True) Minimal Code Example df = pd.DataFrame(‘x’, index=range(3), columns=list(‘abcde’)) df a b … Read more
in tests for the existence of a key in a dict: d = {“key1”: 10, “key2”: 23} if “key1” in d: print(“this will execute”) if “nonexistent key” in d: print(“this will not”) Use dict.get() to provide a default value when the key does not exist: d = {} for i in range(10): d[i] = d.get(i, … Read more
To get the full path to the directory a Python file is contained in, write this in that file: import os dir_path = os.path.dirname(os.path.realpath(__file__)) (Note that the incantation above won’t work if you’ve already used os.chdir() to change your current working directory, since the value of the __file__ constant is relative to the current working … Read more
The Python 3 range() object doesn’t produce numbers immediately; it is a smart sequence object that produces numbers on demand. All it contains is your start, stop and step values, then as you iterate over the object the next integer is calculated each iteration. The object also implements the object.__contains__ hook, and calculates if your … Read more
datetime.strptime parses an input string in the user-specified format into a timezone-naive datetime object: >>> from datetime import datetime >>> datetime.strptime(‘Jun 1 2005 1:33PM’, ‘%b %d %Y %I:%M%p’) datetime.datetime(2005, 6, 1, 13, 33) To obtain a date object using an existing datetime object, convert it using .date(): >>> datetime.strptime(‘Jun 1 2005’, ‘%b %d %Y’).date() date(2005, … Read more
Environment variables are accessed through os.environ: import os print(os.environ[‘HOME’]) To see a list of all environment variables: print(os.environ) If a key is not present, attempting to access it will raise a KeyError. To avoid this: # Returns `None` if key doesn’t exist print(os.environ.get(‘KEY_THAT_MIGHT_EXIST’)) # Returns `default_value` if key doesn’t exist print(os.environ.get(‘KEY_THAT_MIGHT_EXIST’, default_value)) # Returns `default_value` … Read more
This somewhat depends on what platform you are on. The most common way to do this is by printing ANSI escape sequences. For a simple example, here’s some Python code from the Blender build scripts: class bcolors: HEADER = ‘\033[95m’ OKBLUE = ‘\033[94m’ OKCYAN = ‘\033[96m’ OKGREEN = ‘\033[92m’ WARNING = ‘\033[93m’ FAIL = ‘\033[91m’ … Read more
Here’s a generator that yields evenly-sized chunks: def chunks(lst, n): “””Yield successive n-sized chunks from lst.””” for i in range(0, len(lst), n): yield lst[i:i + n] import pprint pprint.pprint(list(chunks(range(10, 75), 10))) [[10, 11, 12, 13, 14, 15, 16, 17, 18, 19], [20, 21, 22, 23, 24, 25, 26, 27, 28, 29], [30, 31, 32, 33, … Read more