Web developer specializing in React, Vue, and front end development.
Sometimes, we want to print a single backslash with Python.
In this article, we’ll look at how to print a single backslash with Python.
To print a single backslash with Python, we pass in '\\' into print.
For instance, we write:
print("\\")
And we see \ printed.
To print a single backslash with Python, we pass in '\\' into print.
Sometimes, we want to create a cartesian product with Python Pandas.
In this article, we’ll look at how to create a cartesian product with Python Pandas.
To create a cartesian product with Python Pandas, we can call the merge method.
For instance, we write:
from pandas import DataFrame
df1 = DataFrame({'col1': [1, 2], 'col2': [3, 4]})
df2 = DataFrame({'col3': [5, 6]})
df = df1.merge(df2, how='cross')
print(df)
to call df1.merge to merge data frtame df1 with df2.
We set how to 'cross' to create a cartesian product and assign the returned data frame to df.
Therefore, df is:
col1 col2 col3
0 1 3 5
1 1 3 6
2 2 4 5
3 2 4 6
To create a cartesian product with Python Pandas, we can call the merge method.
Sometimes, we want to convert hex string to int in Python.
In this article, we’ll look at how to convert hex string to int in Python.
To convert hex string to int in Python, we can call the int function.
For instance, we write:
x = int("deadbeef", 16)
y = int("0xdeadbeef", 0)
print(x)
print(y)
We call int with the hex number with or without the 0x prefix.
If we skip the 0x prefix, then we need to pass in the base as the 2nd argument.
Otherwise, we can pass in 0 for the 2nd argument.
Therefore, x and y are both 3735928559.
To convert hex string to int in Python, we can call the int function.
Sometimes, we want to save an object to disk with Python.
In this article, we’ll look at how to save an object to disk with Python.
To save an object to disk with Python, we can use the pickle module.
For instance, we write:
import pickle
class Company(object):
def __init__(self, name, value):
self.name = name
self.value = value
company = Company('foo', 'bar')
def save_object(obj, filename):
with open(filename, 'wb') as outp:
pickle.dump(obj, outp, pickle.HIGHEST_PROTOCOL)
save_object(company, 'company.pkl')
We have the Company class that we instantiated and assigned to company.
Then we define the save_object function that opens filename and call pickle.dump with obj, the outp file and pickle.HIGHEST_PROTOCOL to always save the file with the latest data.
To save an object to disk with Python, we can use the pickle module.
Sometimes, we want to write JSON data to a file with Python.
In this article, we’ll look at how to write JSON data to a file with Python.
To write JSON data to a file with Python, we can use the open function and the json.dump method.
For instance, we write:
import json
data = {'foo': 1, 'bar': 2}
with open('data.json', 'w', encoding='utf-8') as f:
json.dump(data, f, ensure_ascii=False, indent=2)
to define the data dictionary which we want to write into the JSON file.
Then we call open with 'data.json' to open the data.json file.
'w' lets us open the file with write permission.
encoding sets the text encoding of the file.
Then we call json.dump with data and f to write data to file f.
ensure_ascii set to False to skip ASCII check in the file.
indent is set to 2 to indent each level with 2 spaces.
To write JSON data to a file with Python, we can use the open function and the json.dump method.