How do you select a line from a file in Python?

Use readlines() to Read the range of line from the File The readlines() method reads all lines from a file and stores it in a list. You can use an index number as a line number to extract a set of lines from it. This is the most straightforward way to read a specific line from a file in Python.

How do you write a specific line in a text file in Python?

How to edit a specific line in a text file in Python

1. a_file = open(“sample.txt”, “r”)
2. list_of_lines = a_file. readlines()
3. list_of_lines[1] = “Line2\n”
4. a_file = open(“sample.txt”, “w”)
5. a_file. writelines(list_of_lines)
6. a_file.

How do you get random choices in Python?

To get random elements from sequence objects such as lists, tuples, strings in Python, use choice() , sample() , choices() of the random module. choice() returns one random element, and sample() and choices() return a list of multiple random elements.

How do you read a single line of a text file in Python?

Python readline() method reads only one complete line from the file given. It appends a newline (“\n”) at the end of the line. If you open the file in normal read mode, readline() will return you the string. If you open the file in binary mode, readline() will return you binary object.

How do I extract text from a specific word in python?

Using regular expressions to extract any specific word We can use regular expressions in python to extract specific words from a string. We can use search() method from re module to find the first occurrence of the word and then we can obtain the word using slicing.

How do you overwrite a line in a text file in Python?

Use str. replace() to replace a string within a file strip() to strip the end-line break. Then call str. replace(old, new) to replace old with new in the line. After, concatenate this new string with “\n” to add an end-line break.

How do I extract a specific line from a file in Python?

How to read specific lines of a text file in Python

1. a_file = open(“test_file.txt”)
2. lines_to_read = [0, 2]
3. for position, line in enumerate(a_file): Iterate over each line and its index.
4. if position in lines_to_read:
5. print(line)

How do you make Python choose a random word from a list?

Python

1. Open the file in read mode using with function.
2. Store all data from the file in a string and split the string into words.
3. Count the total number of words.
4. Use random. randint() to generate a random number between 0 and the word_count.
5. Print the word at that position.

How do you give a choice in Python?

Key Points

1. Use if condition to start a conditional statement, elif condition to provide additional tests, and else to provide a default.
2. The bodies of the branches of conditional statements must be indented.
3. Use == to test for equality.
4. X and Y is only true if both X and Y are true.

How do you skip a line in Python?

2 Ways to Skip a Line in Python

1. Using the readlines() method. The readlines() method reads a file and returns a list.
2. Using the readlines() method and List Slicing. Since the readlines() method returns a list, we can perform slicing to skip a specific line.

How do you jump to a specific line in Python?

If you know in advance the position in the file (rather the line number), you can use file. seek() to go to that position. Edit: you can use the linecache. getline(filename, lineno) function, which will return the contents of the line lineno, but only after reading the entire file into memory.

How do I have Python select a random line out of text?

How do I have python select a random line out of my text file and give my output as that number? Assuming the file is relatively small, the following is perhaps the easiest way to do it: import random line = random.choice (open (‘data.txt’).readlines ())

How do I read a string of words from a file?

If the words are instead on separate lines (or spread across lines), use read() instead of readline(). You can read a line from the file using .readline() function and then split the string into a list of strings, based on whatever delimiter you used for the the words in the line . And then random.choice() to randomly select one word from the list.

How to get the next full line from a file?

If the file is very large – you could seek to a random location in the file given the file size and then get the next full line:

How to find newline characters in a file based on length?

For very long file: seek to random place in file based on it’s length and find two newline characters after position (or newline and end of file). Do again 100 characters before or from beginning of file if original seek position was <100 if we ended up inside the last line.