Core pexpect components

spawn class

Controlling the child process

class spawn

pid

The process ID of the child process.

child_fd

The file descriptor used to communicate with the child process.

Handling unicode

By default, spawn is a bytes interface: its read methods return bytes, and its write/send and expect methods expect bytes. If you pass the encoding parameter to the constructor, it will instead act as a unicode interface: strings you send will be encoded using that encoding, and bytes received will be decoded before returning them to you. In this mode, patterns for expect() and expect_exact() should also be unicode.

Changed in version 4.0: spawn provides both the bytes and unicode interfaces. In Pexpect 3.x, the unicode interface was provided by a separate spawnu class.

For backwards compatibility, some Unicode is allowed in bytes mode: the send methods will encode arbitrary unicode as UTF-8 before sending it to the child process, and its expect methods can accept ascii-only unicode strings.

Note

Unicode handling with pexpect works the same way on Python 2 and 3, despite the difference in names. I.e.:

• Bytes mode works with str on Python 2, and bytes on Python 3,

• Unicode mode works with unicode on Python 2, and str on Python 3.

run function

Exceptions

Utility functions