Python Programming | JNTUA | UNIT 3 | Strings |
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This document contains summaries of three lectures (19-21) about strings in Python. It discusses that strings are sequences of characters that can be accessed individually by index and that the len() function returns the length of a string. It also describes how to traverse the characters of a string from beginning to end, slice strings to extract substrings, and that strings are immutable. Additional topics covered include searching for characters in strings, common string methods like count and find, using the in operator to check for substrings, and comparing strings.
![String Sequence
• A string is a sequence
of characters.
• You can access the
characters one at a
time with the [ ]
operator
The expression in brackets is
called an index.](https://image.slidesharecdn.com/pythonl19-l22-210601072806/85/Python-Programming-JNTUA-UNIT-3-Strings-5-320.jpg)
![String slicing
• A segment of a string is
called a slice.
• The operator [n : m]
returns from the nth
char to the (m-1)th char](https://image.slidesharecdn.com/pythonl19-l22-210601072806/85/Python-Programming-JNTUA-UNIT-3-Strings-15-320.jpg)
Python Programming | JNTUA | UNIT 3 | Strings |
- 1. Python Programming Unit – III (Part II) (Lecture 19) Strings
- 2. Python Programming Unit – III (Part II) (Lecture 19) Strings String Sequence String Length String Traversal
- 3. Strings Lecture 19 Lecture 20 String Sequence String Length Immutable Searching String slicing String Traversal String methods in operator Looping & Counting String Comparison Lecture 21
- 4. Strings Lecture 19 String Sequence String Length String Traversal
- 5. String Sequence • A string is a sequence of characters. • You can access the characters one at a time with the [ ] operator The expression in brackets is called an index.
- 6. Strings Lecture 19 String Sequence String Length String Traversal
- 7. String Length len is a built-in function that returns the number of characters in a string How to find last character in string?
- 8. Strings Lecture 19 String Sequence String Length String Traversal
- 9. String Traversal Start at the beginning, select each character in turn and continue until the end is called a traversal.
- 10. Strings Lecture 19 String Sequence String Length String Traversal
- 11. Python Programming Unit – III (Part II) (Lecture 20) Strings
- 12. Python Programming Unit – III (Part II) (Lecture 20) Strings Immutable Searching String slicing
- 13. Strings Lecture 19 Lecture 20 String Sequence String Length Immutable Searching String slicing String Traversal String methods in operator Looping & Counting String Comparison Lecture 21
- 15. String slicing • A segment of a string is called a slice. • The operator [n : m] returns from the nth char to the (m-1)th char
- 17. Immutable Strings are immutable, which means you can’t change an existing string.
- 19. Searching • It takes a character and finds the index where that character appears. • If the character is not found, the function returns -1
- 21. Python Programming Unit – III (Part II) (Lecture 21) Strings
- 22. Python Programming Unit – III (Part II) (Lecture 21) Strings Looping & Counting String methods in operator String Comparison
- 23. Strings Lecture 19 Lecture 20 String Sequence String Length Immutable Searching String slicing String Traversal String methods in operator Looping & Counting String Comparison Lecture 21
- 24. Strings String methods in operator Looping & Counting String Comparison Lecture 21
- 26. Strings String methods in operator Looping & Counting String Comparison Lecture 21
- 27. String methods • A method is similar to a function. • It takes arguments and returns a value
- 28. Strings String methods in operator Looping & Counting String Comparison Lecture 21
- 29. in operator • The word in is a Boolean operator that takes two strings. • if the first string appears as a substring in the second: returns True
- 30. Strings String methods in operator Looping & Counting String Comparison Lecture 21
- 32. Strings String methods in operator Looping & Counting String Comparison Lecture 21
- 33. Python Programming Unit – III (Part III) (Lecture 22) Case Study
- 34. Lecture 22 Reading word lists Search Looping with indices Case Study
- 36. Lecture 22 Reading word lists Search Looping with indices Case Study
- 37. Search
- 38. Search
- 39. Lecture 22 Reading word lists Search Looping with indices Case Study
- 40. Looping with indices L E V E L
- 41. Lecture 22 Reading word lists Search Looping with indices Case Study