How to Set Environment Variables in Python
In Python, using the os.environ variable is the easiest way to set environment variables
Using os.environ Variable
os.environ behaves like a python dictionary, so all the common dictionary operations can be performed. In addition to the get and set ...
How to Get Key by Value in Dictionary in Python
In Python, there are 3 ways to get key by value in dictionary.
Using keys Function
Basically, it separates the dictionary's values in a list, finds the position of the value you have, and gets the key at that position.
The following example:
#!...
How to Return Dictionary Keys as a List in Python
In Python, there are 3 ways to return dictionary keys as a list.
Using keys Function
The dict.keys() function returns a view object that displays a list of all the keys in the dictionary in order of insertion.
See the following example:
#!/usr/...
How to check if a variable exists in Python
In Python, there are 3 ways to check if a variable exists.
Using locals Function
The locals() function returns the dictionary of the current local symbol table.
#!/usr/bin/python3
vName = 1
if 'vName' in locals():
print("exists")
exists
...
How to Copy a Dictionary in Python
In Python, there are 4 ways to copy a dictionary.
Using dict Method
If you want to copy the dict, you have to do so explicitly with:
#!/usr/bin/python3
a = {"a": 1, "b": 2}
# Copy
b = dict(a)
b['a'] = 3
print(a)
print(b)
{'a': 1, 'b': 2}
{'...
How to Remove Duplicates in List in Python
In Python, there are 3 ways to remove duplicates in list.
Using Built-in set Function
The built-in set() function returns a new set object, optionally with elements taken from iterable. If you later need a real list again, you can similarly pass the...
How to Delete an Item from a Dictionary in Python
In Python, there are 2 ways to delete an item from a dictionary.
Using del Statement
The easiest way to delete an item from a dictionary in Python:
#!/usr/bin/python3
m = {"a":1, "b":2}
# remove a
if 'a' in m:
del m['a']
print(m)
{'b': 2...
How to Count the Occurrences of a List Item in Python
In Python, there are 3 ways to count the occurrences of a list item.
Using count Method
The str.count() method returns the number of non-overlapping occurrences of substring sub in the range [start, end]. Optional arguments start and end are interpr...
How to Merge two Dictionaries into a new Dictionary in Python
In Python, there are 3 ways to merge two dictionaries into a new dictionary.
Using Additional Unpacking Generalizations
Starting with Python 3.5, we can merge in with literal notation as well. See the following example:
#!/usr/bin/python3
# -*-...
How to convert string to json in Python
Converting Json to string in Python.Decoding JSON
To convert string to json in Python, use the json.loads() function. The json.loads() is a built-in Python function that accepts a valid json string and returns a dictionary to access all elements. The...
How to check if key exists in a dictionary in Python
Check if a given key already exists in a dictionary.Using the in operator
In this method, we use the membership operator in. This operator is used to check if one value is a member of another. It returns a boolean value.
dict = {"GMT": 0, "BST": 1}
...