How to concatenate strings in python

In this python tutorial, we will discuss how to concatenate strings in python.

How to concatenate strings in python

We will also discuss on the below topics here

• How to concatenate two strings in python. Can we add two strings in python?
• How to concatenate strings and int in python
• How to concatenate lists in python or join strings python list
• Python concatenate strings in a list
• Python concatenate strings in for loop
• Python concatenate strings in the print statement
• Python concatenate strings with a separator
• Python concatenate strings with space
• Python concatenate strings multiple lines
• Python concatenate strings and numbers
• Python concatenate string and float
• Python concatenate strings and list
• Python concatenate strings and bytes
• Python concatenate strings array
• Python join strings by comma
• Python add string beginning
• Python string add a backslash
• Python string concatenation best practice
• How to concatenate two lists in python
• How to concatenate two dictionaries in python
• How to concatenate dictionaries in python
• How to concatenate string and variable in python

Are you new to Python? Check out the basic tutorial and Python Hello World Program

How to concatenate strings in python

Now, let us see how to concatenate strings in python, how to concatenate two strings in python. Can we add two strings in python?

Yes, we can add or concatenate strings. There are multiple ways to concatenate strings. See below for all the approaches.

1- Using + operator

Using + operator is the most common way to concatenate strings in python. You can concatenate two strings using this operator.

The arguments should be string if you are using + operator to concatenate.

Example:

myvar1 = "Python"

myvar2 = "Guides"

# use + operator to concatenate both strings

myvar3 = myvar1 + myvar2

print(myvar3)

The out put will be

PythonGuides

Let’s run the above code and see the output

How to concatenate strings in python

One important note here is python doesn’t support implicit string conversion. If you try to concatenate a string with a non-string type then it will throw an error

Let’s check this

myvar1 = 3

myvar2 = "Python"

myvar3 = myvar1 + myvar2 

print(myvar3)

Output will be an error “TypeError: unsupported operand type(s) for +: ‘int’ and ‘str'”.

myvar3 = myvar1 + myvar2
TypeError: unsupported operand type(s) for +: 'int' and 'str'

See here

2- Using join() method

You can concatenate strings using join() method.

Example:

myvar1 = "Python"

myvar2 = "Guides"

# use join() to concatenate both strings

myvar3 = "".join([myvar1, myvar2])

print(myvar3)

The output will be

PythonGuides

See here

3- Using % Operator

We can also concatenate the strings using % operator

% operator can also be used to format the string.

For example:

myvar1 = "Python"

myvar2 = "Guides"

# use % operator to concatenate both strings

print("% s % s"%(myvar1,myvar2))

In the above example, We have used two %s which shows that myvar1 and myvar2 contains string data type.

The output will be

Python Guides

See here

4- Using format() function

We can also concatenate the strings using format() function. It allows us to concatenate the strings using positional formatting.

{ } (curly braces) are used along with this format() function to position the string. Each string will have one { } (curly braces).

Example:

myvar1 = "Python"

myvar2 = "Guides"

# use format() to concatenate both strings

print("{}{}".format(myvar1, myvar2))

The output will be

PythonGuides

See here

How to concatenate strings and int in python

In Python, We cannot use + operator to concatenate one string and int type. We cannot concatenate a string with a non-string type. It will throw an error “TypeError: unsupported operand type(s) for +: ‘int’ and ‘str'”.

Below are the approaches we can use to concatenate one string and an int type.

1- Using str() function

We can use str() to concatenate one string and an int type.

Example:

myvar1 = "Python"

myvar2 = 3

# use str() to concatenate an int with a string

print(myvar1 + str(myvar2))

The output will be

Python3

See here

2- Using % Operator

We can use % Operator to concatenate one string and an int type.

Example:’

myvar1 = "Python"

myvar2 = 3

# use % operator to concatenate string with int

print("% s % s"%(myvar1,myvar2))

The output will be

Python 3

3- Using format() function

We can use format() function to concatenate one string and an int type.

One more benefit of format() is no need to convert integers into a string before concatenating the data.

Example:

myvar1 = "PythonGuides"

myvar2 = 2020

# use format() to concatenate string with int

print("{}{}".format(myvar1, myvar2))

Output will be

PythonGuides2020

See output here

4- Using f strings

We can use f strings to concatenate one string and an int type.

Note: f strings supports only python 3.6 and above versions.

Example:

myvar1 = "PythonGuides"

myvar2 = 2020

# use format() to concatenate string with int

print(f"{myvar1} {myvar2}")

Output will be

PythonGuides 2020

See the output here

How to concatenate lists in python or How do I combine multiple lists into one python?

There are multiple ways to concatenate multiple lists in python.

1- Using for loop

We can use for loop to concatenate multiple lists in python.

We can traverse the second list and keep appending the elements in the first list using for loop.

Example:

myvar1 = [11, 13, 15, 17, 19]

myvar2 = [23, 25, 27, 29, 31]

# using for loop to concatenate lists

for i in myvar2 :
	myvar1.append(i)
# Printing my concatenated list
print("My concatenated list using for loop : "
      + str(myvar1))

The output will be

My concatenated list using for loop : [11, 13, 15, 17, 19, 23, 25, 27, 29, 31]

See the output here

2- Using + operator

You can use + operator to concatenate multiple lists in python.

This is one of the easy and very simple approach to concatenate multiple lists in python.

Example:

myvar1 = [11, 13, 15, 17, 19]

myvar2 = [23, 25, 27, 29, 31]

# using + operator to concatenate lists

myvar3 = myvar1 + myvar2
# Printing my concatenated list
print("My concatenated list using + operator : "
      + str(myvar3))

The output will be

My concatenated list using + operator : [11, 13, 15, 17, 19, 23, 25, 27, 29, 31]

See the output here

3- Using extend() function

You can use extend() to concatenate multiple lists in python.

Example:

mylist1 = [11, 13, 15, 17, 19]

mylist2 = [23, 25, 27, 29, 31]

# using extend() to concatenate lists

mylist1.extend(mylist2)

# Printing my concatenated list
print("My concatenated list using extend() : "
      + str(mylist1))

The output will be

My concatenated list using extend() : [11, 13, 15, 17, 19, 23, 25, 27, 29, 31]

See the output here

4- Using * operator

Using * operator we can also concatenate multiple lists in python.

This operator will work only with python 3.6 and above versions.

Example:

mylist1 = [11, 13, 15, 17, 19]

mylist2 = [23, 25, 27, 29, 31]

# using * operator to concatenate lists

mylist3 = [*mylist1, *mylist2]

# Printing my concatenated list
print("My concatenated list using * operator : "
      + str(mylist3))

The output will be

My concatenated list using * operator : [11, 13, 15, 17, 19, 23, 25, 27, 29, 31]

See here for the output

5- Using list comprehension

We can also concatenate multiple lists using list comprehension.

Example:

mylist1 = [11, 13, 15, 17, 19]

mylist2 = [23, 25, 27, 29, 31]

# using list comprehension to concatenate lists

mylist3 = [b for a in [mylist1, mylist2] for b in a]

# Printing my concatenated list
print("My concatenated list using list comprehension : "
      + str(mylist3))

The output will be

My concatenated list using list comprehension : [11, 13, 15, 17, 19, 23, 25, 27, 29, 31]

See the output here

6- Using itertools.chain() method

We can also concatenate multiple lists itertools.chain() method.

Note: We need to import itertools namespace.

Example:

import itertools

mylist1 = [11, 13, 15, 17, 19]

mylist2 = [23, 25, 27, 29, 31]

# using itertools.chain() method to concatenate lists

mylist3 = list(itertools.chain(mylist1, mylist2))

# Printing my concatenated list
print("My concatenated list using itertools.chain() method : "
      + str(mylist3))

The output will be

My concatenated list using itertools.chain() method : [11, 13, 15, 17, 19, 23, 25, 27, 29, 31]

See the output here

Python concatenate strings in a list

To concatenate strings in a list we will use for loop and the “+ ” operator is the most common way to concatenate strings in a list python.

Example:

l = ['This','is','python']
my_str = ""
for i in l:
    my_str += str(i)
str = my_str[0:]
print(my_str)

To get the output, I have used print(my_str). You can refer to the below screenshot for the output.

Python concatenate strings in a list

Python concatenate strings in for loop

Now, let us see how to concatenate strings in for loop

To concatenate strings we will use for loop, and the “+ ” operator is the most common way to concatenate strings in python.

Example:

v = ['Welcome', 'to', 'Python']
my_str = ""
for item in v:
    my_str += item
print(my_str)

To get the output, I have used print(my_str). You can refer to the below screenshot for the output.

Python concatenate strings in for loop

Python concatenate strings in the print statement

Here, we can see how to concatenate strings in the print statement

To concatenate strings we will use “+ ” operator in the print statement.

Example:

S_name = "Tom"
print ("Welcome" + S_name)

To get the output, I have used (“Welcome” + S_name). You can refer to the below screenshot for the output.

Python concatenate strings in the print statement

Python concatenate strings with a separator

Now, we will see how to concatenate strings with a separator

We can also concatenate the strings by using the ‘,’ separator in between the two strings, and the “+ ” operator is used to concatenate the string with a comma as a separator.

Example:

s1 = 'Python'
s2 = 'Guides'
str = s1 + ',' + s2
print(str)

To get the output, I have used print(str). You can refer to the below screenshot for the output.

Python concatenate strings with a separator

Python concatenate strings with space

Here, we will see how to concatenate strings with space

We can also concatenate the strings by using the space ‘ ‘ in between the two strings, and the “+” operator is used to concatenate the string with space.

Example:

s1 = 'Pizza'
s2 = 'Burger'
str = s1 + ' ' + s2
print(str)

To get the output, I have used print(my_str). You can refer to the below screenshot for the output.

Python concatenate strings with space

Python concatenate strings multiple lines

Now, we will see python concatenate strings multiple lines

In Python, we can concatenate strings multiple lines by breaking the lines in parentheses. Here, we have used “()” to concatenate string multiple lines.

Example:

my_str = ('Welcome to Python tutorial.'
     ' Python is one of the most famous language'
     ' and everyone enjoy coding in python ')
print(my_str)

To get the output, I have used print(my_str). You can refer to the below screenshot for the output.

Python concatenate strings multiple lines

Python concatenate strings and numbers

Now, we will see how to concatenate strings and numbers

In Python, We cannot use the + operator to concatenate one string and number type. We cannot concatenate a string with a non-string type. We will use str() to convert the number to string type and then it will be concatenated.

Example:

f = 'Pizza'
a = 150
print(f + str(a))

To get the output, I have used print(f + str(a)). You can refer to the below screenshot for the output.

Python concatenate strings and numbers

Python concatenate string and float

Let’s see how to concatenate strings and float

In Python, We cannot use the + operator to concatenate one string and float type. We cannot concatenate a string with a non-string type. We will use str() to convert the float to string type and then it will be concatenated.

Example:

s= 'Python'
f = 3.5
c = str(f)
print(s + c)

To get the output, I have used print(s + c). You can refer to the below screenshot for the output.

Python concatenate string and float

Python concatenate strings and list

Now, we will see how to concatenate strings and list

To concatenate strings and lists we will use the + operator and the .join() is used to concatenate strings and lists in python.

Example:

l1 = ['Python','C','C++']
my_str = 'I like to code in: '
print(my_str + ','.join(l1))

To get the output, I have used print(my_str + ‘,’.join(l1)). You can refer to the below screenshot for the output.

Python concatenate strings and list

Python concatenate strings and bytes

Let’s see how to concatenate strings and bytes

To concatenate strings and bytes we will use the + operator to concatenate, and also we use str() to convert the bytes to string type, and then it will be concatenated.

Example:

my_str = 'XXXYYYZZZ '
bytes = b'\xee\xba\xf3\xca'
print(my_str + str(bytes))

To get the output, I have used print(my_str + str(bytes)). You can refer to the below screenshot for the output.

Python concatenate strings and bytes

Python concatenate strings array

Let us see how to concatenate strings array

To concatenate strings array we will import numpy as np. Here, a1 and a2 are two strings arrays that will get concatenated using “np.char.add(a1, a2)”.

Example:

import numpy as np
a1 = np.array(['Mango', 'Orange'])
a2 = np.array([' Apple', ' Grapes'])
n_arr = np.char.add(a1, a2)
print(n_arr)

To get the output, I have used print(n_arr). You can refer to the below screenshot for the output.

Python concatenate strings array

Python join strings by comma

Now, we will see python join strings by comma

To join strings by comma we will use the comma separator and the join() method as ‘,’.join(my_str).

Example:

my_str = 'Python' 'Guides'
res = ','.join(my_str)
print(res)

To get the output, I have used print(res). You can refer to the below screenshot for the output.

Python join strings by comma

Python add string beginning

Here, we will see python add string beginning

In python, to add string at the beginning we will use for loop to iterate, and it will insert the given string at the beginning of all the items.

Example:

val = [101,102,103]
print(['student{0}'.format(i) for i in val])

To get the output, I have used print([‘student{0}’.format(i) for i in val]). You can refer to the below screenshot for the output.

Python add string beginning

Python string add a backslash

Let’s see python string add a backslash

In python, to add a backslash in a string we will use “my_str.replace(” ‘ “, “\\’ “)” and then the single backslash will be added to the string.

Example:

my_str = "Python Guide's Tutorial"
res = my_str.replace("'", "\\'")
print(res)

To get the output, I have used print(res). You can refer to the below screenshot for the output.

Python string add a backslash

Python string concatenation best practice

The best practice for string concatenation in Python is by using the simple concatenation + operator. This is because it’s readable and fast. Also, if you are working with two strings then append() can also be the best practice. If you are concatenating a list and string, then the preferred way is to use join() as it makes it more readable.

How to concatenate two dictionaries in python

Here, we will discuss how to concatenate two dictionaries or merging two dictionaries in python.

There are few ways to concatenate two dictionaries in python.

1- Using update() function

We can concatenate two dictionaries in python using update() method.

Example:

mydict1 = {'a': 10, 'b': 8}
mydict2 = {'d': 6, 'c': 4}
# Python code to concatenate dict using update() method
def Merge(mydict1, mydict2):
    return (mydict2.update(mydict1))

print(Merge(mydict1, mydict2))

# changes made in dict2
print(mydict2)

The output will be

None
{'d': 6, 'c': 4, 'a': 10, 'b': 8}

See the output here

2- Using ** (double star)

You can concatenate two dictionaries in python using ** (double star).

Example:

mydict1 = {'a': 10, 'b': 8}
mydict2 = {'d': 6, 'c': 4}

def Merge(mydict1, mydict2):
    output = {**mydict1, **mydict2}
    return output

mydict3 = Merge(mydict1, mydict2)
print(mydict3)

The output will be

{'a': 10, 'b': 8, 'd': 6, 'c': 4}

See the output here

Conclusion:

Python is the most popular open-source object-oriented programming language and it is easy to learn and syntax wise it is very simple.

This python tutorial explains the below points:

• How to concatenate strings in python
• How to concatenate two strings in python. Can we add two strings in python?
• How to concatenate strings and int in python
• Python concatenate strings in a list
• Python concatenate strings in for loop
• Python concatenate strings in the print statement
• Python concatenate strings with a separator
• Python concatenate strings with space
• Python concatenate strings multiple lines
• Python concatenate strings and numbers
• Python concatenate string and float
• Python concatenate strings and list
• Python concatenate strings and bytes
• Python concatenate strings array
• Python join strings by comma
• Python add string beginning
• Python string add a backslash
• Python string concatenation best practice
• How to concatenate lists in python or join strings python list
• How to concatenate two lists in python
• How to concatenate two dictionaries in python
• How to concatenate dictionaries in python
• How to concatenate string and variable in python