Strings in Python

Updated on May 20, 2019
Sam Shepards profile image

I'm a software developer with a great interest in data analysis and statistics.

Unlike other programming languages like C, C++ or Java, Python does not have the concept of a character. In fact, if we enclose a single character within single quotes, Python interpreter interprets it as a string with only one character. As discussed earlier, Python string values can be defined using either single or double quotes.

Python Strings are immutable. But the variable that points to a string in memory can be modified in such a way that it points to a different one. It is possible to use slice operator to make it seem like updating parts of the same string, but in reality, all that python interpreter does is to make the string variable point to a new string in memory.


firstString = "Hello"
secondString = 'World'
print("firstString: ", firstString)
print("secondString: ", secondString)
secondString = secondString[0:1] + 'alter'
print("secondString after modification: ", secondString)

The output of the above program will be:

firstString:  Hello
secondString:  World
secondString after modification:  Walter

Note how the result of concatenation is assigned explicitly to secondString at line number 7. If we don’t assign the value to secondString, the value printed for the last print statement will be “World”. This is because strings in python are immutable and doing a concatenation using + operation actually creates a new string in memory without altering the existing string objects.

Operators in String

In the previous section, we saw one special operator + which was used to concatenate two string values. We also saw how to use slice operators on String. We will learn about the remaining important special operators on Python string in this section.

The Repetition Operator(*)

It creates a new string after repeating the original string on the LHS of the asterisk as many times as denoted by the number following it.

The In And Not In Operators

These membership operators can be used to find out whether a given character is part of the string or not.

The % Operator

This performs string formatting.

The Raw String Operator(r/R)

Usually, when we use \ before certain characters, they may be translated to escape characters. In order to print these escape character strings we can use R or r just before the sequence.

firstString = "Hello"
secondString = 'World'
# Repetition operator
print(firstString * 2)

# Membership operator
if 'e' in firstString:
    print("Found letter e in firstString value")
    print("Did not find letter e in firstString value")
if 'a' not in secondString:
    print("secondString value doesnt contain letter a")
    print("secondString value contains letter a")
# prints hexadecimal value of 1240 using % formatting operator
print("1240 in hex is %x" % 1240)

print("Newline is represented by: ", r'\n')

Output for the above code will be:

Found letter e in firstString value
secondString value doesnt contain letter a
1240 in hex is 4d8
Newline is represented by:  \n

Important String Functions

There are many built-in functions in Python that helps one to manipulate strings. Some of the important ones are:

  • isalpha(), isalnum() and isdigit() : returns true if all characters in strings are alphabetic, alphanumeric and numeric respectively.
  • Islower() and isupper() – returns true if all characters are lowercase and uppercase respectively.
  • join(sequence) – returns a string formed by concatenating the strings in sequence passed. The different strings will be separated by the string on which the join operation is performed.
  • lower(), capitalize() and upper() – converts the given string to lower case form, capitalized form ( only first letter remains capitalized) and upper cases respectively.
  • Decode() and encode() – decodes and encodes given string using the encoding format.
  • len() – returns the length of the string.
  • lstrip() – trims the given string by removing leading whitespaces.
  • Max() and min() – returns maximum and minimum characters in the given string.

startswith() and endswith() – checks if a given string starts or ends with the given string sequence.

firstString = "hello"
print("firstString.islower()? ",firstString.islower())

separator = '_'
seq = ["This", "is", "a", "python", "tutorial"]
newStr = separator.join(seq)
print("length of new string : ", len(newStr))


if newStr.startswith("This"):
    print("newStr formed using join operation starts with This")
    print("newStr formed using join operation does not start with This")

Output for the above program will be:

firstString.islower()?  True
length of new string :  25
newStr formed using join operation starts with This

© 2019 Sam Shepards


    0 of 8192 characters used
    Post Comment

    No comments yet.


    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

    Show Details
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)
    ClickscoThis is a data management platform studying reader behavior (Privacy Policy)