Rstrip

As explained in Tiny Python Projects: Learn coding and testing with puzzles and games

str.rstrip() is a Python string method that returns a copy of a string with trailing whitespace characters removed.

str.rstrip() returns a new string with trailing whitespace removed. It is especially useful for removing the newline commonly left at the end of text read from a file. section 5.1 section 7.3.2

Use rstrip() to normalize text at input boundaries:

• Chain it after reading a complete file: open(file).read().rstrip(). section 5.5.2
• Apply it to each line before storing or processing that line. section 7.3.2
• Keep the original string unchanged; the method returns a cleaned copy. section 5.5.2

Remove a file's final newline

>>> text = open(file).read().rstrip() >>> text 'The quick brown fox jumps over the lazy dog.' For line-oriented input, the same operation appears as line.rstrip(), leaving the line's content without its trailing whitespace. section 5.1 section 7.3.2

Figure 5.6 The open() function returns a file handle (fh). The fh.read() function returns a str. The str.rstrip() function returns a new str with the whitespace removed from the right side. All these functions can be chained together.

Trace the chained pipeline from open() to read() to rstrip(), including the changing value type at each step. section 5.5.2

How Tiny Python Projects: Learn coding and testing with puzzles and games covers it

How deep it goes

Defines right-side whitespace removal and demonstrates chained and line-by-line use, without exploring optional character arguments.

Examples

Demonstrates open(file).read().rstrip() and line.rstrip() while building cleaned lookup values.

What it assumes

Assumes familiarity with strings and method calls while demonstrating file handles, read(), and chained operations.

What you can do after

Apply it to remove trailing whitespace from strings read from files or processed line by line.

How it connects

Connects string methods with file reading, command-line arguments, and newline handling.

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Related concepts

• newlineaddresses · A newline is a character or character sequence that marks the boundary between consecutive lines of text.
• trimalternative to · Trim is a string operation that returns a string or view with specified characters, typically whitespace, removed from its beginning and end.
• stringproduces · A string is a programming-language value representing an ordered sequence of characters or character units as text.
• whitespace characteraddresses · A whitespace character is a nonprinting character representing spacing or separation in text, such as a space, tab, or line break.

This explainer was generated by Manning's knowledge graph from the text of Tiny Python Projects: Learn coding and testing with puzzles and games. The section links point to the parts of the book it draws on.