File read example

A subsequent call to open this file with CreateFile will fail until the handle is closed. The following example uses CreateFile to open an existing file for reading and ReadFile to read up to 80 characters synchronously from the file. In this case, CreateFile succeeds only if the specified file already exists in the current directory. A subsequent call to open this file with CreateFile will succeed if the call uses the same access and sharing modes.

Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Reading from file using read function Ask Question. Asked 8 years, 2 months ago. Active 10 months ago. Viewed k times. Improve this question. Jonathan Leffler k gold badges silver badges bronze badges. Wit Wit 1 1 gold badge 1 1 silver badge 8 8 bronze badges.

And the question is? Ohh sry. How to read only one line — Wit. However, you can set the encoding through the outputEncoding parameter. DataWeave expressions are embeddable inside operations that generate payloads and other values. Having the correct mimeType set helps DataWeave auto-assign types and also generate the correct outputs. While developing Mule apps, you can save folders and files in the resources folder. For example, if you want to define a folder named MyFiles in the resources folder, and a file named Example.

You can set the lock parameter to true to prevent other processes from accessing a file while it is being read. You must take that into consideration before relying on this lock. If you want to read the file contents returned by the Read operation, but you are not sure if the file is still being written to, you can use the TimeBetweenSizeChecks parameter, which works with the TimeBetweenSizeCheckUnit parameter.

Combined, these two parameters perform two size checks:. One when the flow reaches a point where the stream is about to be consumed. Here, we use the Id columns as the dataframe index. In the above example, you can see that the Id column is used as the row index of the dataframe df.

You can also specify the subset of columns to read from the dataset. Pass the subset of columns you want as a list to the usecols parameter. Particularly useful when you want to read a small segment of a large file. These are just some of the things you can do when reading a CSV file to dataframe. Pandas dataframes also provide a number of useful features to manipulate the data once the dataframe has been created.

With this, we come to the end of this tutorial. The code examples and results presented in this tutorial have been implemented in a Jupyter Notebook with a python version 3.

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