import sys, os myPath = os.path.dirname(os.path.abspath(__file__)) sys.path.insert(0, myPath + '/../') # from https://stackoverflow.com/questions/10253826/path-issue-with-pytest-importerror-no-module-named-yadayadayada
Here is what the above code is Doing:
1. Get the directory of the current file.
2. Add the parent directory to the path.
3. Import the module.
This is a common pattern in Python.
MyModel.objects.filter(field__isnull = False) Here is what the above code is Doing: 1. It’s creating a queryset of all MyModel objects that have a non-null value for field. 2. It’s iterating over that queryset, and for each object it’s retrieving the value of field. 3. It’s printing out the value of field. The above code is…
a = [1, 2, 3, 4, 5] a[1::2] # returns 2, 4 a[::2] #returns 1, 3, 5 Here is what the above code is Doing: 1. a[1::2] a[1] is the starting index a[::2] is the step size a[1::2] is the starting index and the step size 2. a[::2] a[::2] is the step size a[::2] is…
data = [‘alfa’, ‘bravo’, ‘charlie’, ‘delta’] print(ft.reduce(lambda x, y: x + (“.” if x else “”) + y[0], data, “”)) # a.b.c.d Here is what the above code is Doing: 1. The first time the lambda function is called, x is the initial value (the empty string) and y is the first item in the…
import os with open(os.path.join(sys.path[0], “my_file.txt”), “r”) as f: print(f.read()) Here is what the above code is Doing: 1. We import the os module. 2. We use the os.path.join() function to join the current directory (sys.path[0]) with the name of the file we want to open. 3. We open the file in read mode. 4. We…
df[‘column_name’].value_counts() df.groupby([‘column_name’]).count() #Each returns the results in a pandas Series. Here is what the above code is Doing: 1. df.groupby([‘column_name’]) creates a groupby object. 2. .count() counts the number of times each value appears in the column.
import struct def rawbytes(s): “””Convert a string to raw bytes without encoding””” outlist = [] for cp in s: num = ord(cp) if num < 255: outlist.append(struct.pack('B', num)) elif num < 65535: outlist.append(struct.pack('>H’, num)) else: b = (num & 0xFF0000) >> 16 H = num & 0xFFFF outlist.append(struct.pack(‘>bH’, b, H)) return b”.join(outlist) Here is what…