f = open("test.txt",'w')
here we open test.txt in write mode.
pwd - Shows present Working directory:
<pre><code class="lang-csharp">'/home/jovyan/work'
</code></pre>
ls - shows the list of files in directory
<pre><code class="lang-csharp">README.md sample-code.ipynb test.txt Untitled.ipynb
</code></pre>
w - truncate
a - append

f = open("test.txt",'w')

here we open test.txt in write mode.

pwd - Shows present Working directory:

```csharp
'/home/jovyan/work'
```

ls - shows the list of files in directory

```csharp
README.md  sample-code.ipynb  test.txt  Untitled.ipynb
```

w - truncate

a - append

Files in Python